Dodge Ram 2004 Service Manual

TABLE OF CONTENTS

1.0 INTRODUCTION .........................................................1

1.1 SYSTEM COVERAGE ...............................................1

1.2 SIX-STEP TROUBLESHOOTING PROCEDURE ..........................1

2.0 IDENTIFICATION OF SYSTEM .............................................1

3.0 SYSTEM DESCRIPTION AND FUNCTIONAL OPERATION ......................1

3.1 AIRBAG SYSTEM ...................................................2

3.1.1 DRIVER AIRBAG............................................2

3.1.2 CLOCKSPRING.............................................3

3.1.3 PASSENGER AIRBAG .......................................3

3.1.4 PASSENGER AIRBAG ON-OFF SWITCH .......................3

3.1.5 SEAT BELT TENSIONER ....................................4

3.1.6 SIDE IMPACT SENSORS.....................................4

3.1.7 CURTAIN AIRBAGS .........................................4

3.1.8 SPECIAL TOOLS............................................4

3.1.9 AIRBAG DIAGNOSTIC TROUBLE CODES.......................5

3.1.9.1 ACTIVE CODES ............................................5

3.1.9.2 STORED CODES ...........................................5

3.2 AUDIO SYSTEM ....................................................5

3.2.1 REMOTE RADIO CONTROLS .................................6

3.2.2 AMPLIFIER (PREMIUM SYSTEM)..............................6

3.2.3 NAVIGATION RADIO.........................................6

3.3 COMMUNICATION ..................................................6

3.4 COMPASS MINI-TRIP COMPUTER (CMTC) .............................8

3.4.1 VEHICLE INFORMATION DISPLAY.............................9

3.5 DOOR AJAR SYSTEM ..............................................11

3.6 ELECTRICALLY HEATED SYSTEMS ..................................11

3.7 EXTERIOR LIGHTING SYSTEM ......................................11

3.8 FRONT CONTROL MODULE .........................................11

3.8.1 CONTROLLED POWER FEEDS ..............................12

3.8.2 RELAY CONTROLS ........................................12

3.8.3 ELECTRICAL INPUTS ......................................13

3.9 HEATING & A/C SYSTEM ...........................................13

3.9.1 SYSTEM AVAILABILITY .....................................13

3.9.2 SYSTEM CONTROLS.......................................13

3.9.3 SYSTEM REVISIONS.......................................14

3.9.4 SYSTEM DIAGNOSTICS ....................................14

3.10 INSTRUMENT CLUSTER............................................15

3.10.1 DIAGNOSTIC SELF TEST ...................................16

3.11 INTERIOR LIGHTING ...............................................16

3.12 POWER DOOR LOCKS/REMOTE KEYLESS ENTRY .....................16

3.12.1 AUTOMATIC DOOR LOCKS .................................16

3.12.2 CENTRAL LOCKING/UNLOCKING ............................16

3.12.3 DOOR LOCK INHIBIT.......................................16

3.12.4 ENHANCED ACCIDENT RESPONSE ..........................16

3.13 REMOTE KEYLESS ENTRY .........................................16

3.14 TELECOMMUNICATIONS ...........................................17

3.14.1 HANDS FREE PHONE ......................................17

3.15 VEHICLE THEFT SECURITY SYSTEM.................................17

3.16 WINDSHIELD WIPERS/WASHERS....................................17

TABLE OF CONTENTS - Continued

3.17 USING THE DRBIIIT ................................................18

3.18 DRBIIIT ERROR MESSAGES AND BLANK SCREEN .....................18

3.18.1 DRBIIIT DOES NOT POWER UP..............................18

3.18.2 DISPLAY IS NOT VISIBLE ...................................18

4.0 DISCLAIMERS, SAFETY, WARNINGS ......................................18

4.1 DISCLAIMERS.....................................................18

4.2 SAFETY..........................................................18

4.2.1 TECHNICIAN SAFETY INFORMATION.........................18

4.2.2 VEHICLE PREPARATION FOR TESTING.......................19

4.2.3 SERVICING SUB-ASSEMBLIES ..............................19

4.2.4 DRBIIIT SAFETY INFORMATION .............................19

4.3 WARNINGS.......................................................19

4.3.1 VEHICLE DAMAGE WARNINGS ..............................19

4.3.2 ROAD TESTING A COMPLAINT VEHICLE......................19

5.0 REQUIRED TOOLS AND EQUIPMENT .....................................20

6.0 GLOSSARY OF TERMS..................................................20

7.0 DIAGNOSTIC INFORMATION AND PROCEDURES ...........................21

AIRBAG

ACCELEROMETER 1....................................................22

ACCELEROMETER 2....................................................22

DEPLOYMENT DATA RECORD FULL.......................................22

INTERNAL 1 ...........................................................22

INTERNAL 2 ...........................................................22

OUTPUT DRIVER 1 .....................................................22

STORED ENERGY FIRING 1..............................................22

INTERNAL MODULE TEST ...............................................22

AIRBAG WARNING INDICATOR OPEN .....................................24

AIRBAG WARNING INDICATOR SHORT ....................................24

AIRBAG WARNING INDICATOR TEST ......................................24

CALIBRATION MISMATCH................................................27

CLUSTER MESSAGE MISMATCH .........................................30

DRIVER SEAT BELT TENSIONER CIRCUIT OPEN............................32

DRIVER SEAT BELT TENSIONER CIRCUIT SHORT ..........................35

DRIVER SEAT BELT TENSIONER SHORT TO BATTERY.......................38

DRIVER SEAT BELT TENSIONER SHORT TO GROUND.......................41

DRIVER SQUIB 1 CIRCUIT OPEN .........................................44

DRIVER SQUIB 1 CIRCUIT SHORT ........................................47

DRIVER SQUIB 1 SHORT TO BATTERY ....................................50

DRIVER SQUIB 1 SHORT TO GROUND ....................................53

DRIVER SQUIB 2 CIRCUIT OPEN .........................................56

DRIVER SQUIB 2 CIRCUIT SHORT ........................................59

DRIVER SQUIB 2 SHORT TO BATTERY ....................................62

DRIVER SQUIB 2 SHORT TO GROUND ....................................65

LEFT CURTAIN SQUIB 1 CIRCUIT OPEN ...................................68

LEFT CURTAIN SQUIB 1 CIRCUIT SHORT..................................71

LEFT CURTAIN SQUIB 1 SHORT TO BATTERY ..............................74

LEFT CURTAIN SQUIB 1 SHORT TO GROUND ..............................77

LEFT SIDE IMPACT SENSOR 1 INTERNAL 1 ................................80

TABLE OF CONTENTS - Continued

LOSS OF IGNITION RUN - START .........................................82

LOSS OF IGNITION RUN ONLY ...........................................86

MISSING CURRENT VIN .................................................90

MODULE NOT CONFIGURED FOR PAB OFF SWITCH ........................93

NO CLUSTER MESSAGE ................................................96

NO LEFT SIDE IMPACT SENSOR 1 COMMUNICATION........................98

NO PCI LOOPBACK....................................................102

NO PCI TRANSMISSION ................................................102

NO RIGHT SIDE IMPACT SENSOR 1 COMMUNICATION .....................107

OCCUPANT CLASSIFICATION MODULE CONFIGURATION MISMATCH .........111

PASSENGER AIRBAG ON-OFF SWITCH OPEN .............................113

PASSENGER AIRBAG ON-OFF SWITCH SHORT TO BATTERY ................116

PASSENGER AIRBAG ON-OFF SWITCH SHORT TO GROUND ................119

PASSENGER OFF INDICATOR CIRCUIT SHORT TO BATTERY................121

PASSENGER OFF INDICATOR CIRCUIT SHORT TO GROUND ................124

PASSENGER SEAT BELT TENSIONER CIRCUIT OPEN ......................128

PASSENGER SEAT BELT TENSIONER CIRCUIT SHORT .....................131

PASSENGER SEAT BELT TENSIONER SHORT TO BATTERY .................134

PASSENGER SEAT BELT TENSIONER SHORT TO GROUND .................137

PASSENGER SQUIB 1 CIRCUIT OPEN ....................................140

PASSENGER SQUIB 1 CIRCUIT SHORT...................................143

PASSENGER SQUIB 1 SHORT TO BATTERY...............................146

PASSENGER SQUIB 1 SHORT TO GROUND ...............................149

PASSENGER SQUIB 2 CIRCUIT OPEN ....................................152

PASSENGER SQUIB 2 CIRCUIT SHORT...................................155

PASSENGER SQUIB 2 SHORT TO BATTERY...............................158

PASSENGER SQUIB 2 SHORT TO GROUND ...............................161

RIGHT CURTAIN SQUIB 1 CIRCUIT OPEN.................................164

RIGHT CURTAIN SQUIB 1 CIRCUIT SHORT................................167

RIGHT CURTAIN SQUIB 1 SHORT TO BATTERY............................170

RIGHT CURTAIN SQUIB 1 SHORT TO GROUND ............................173

RIGHT SIDE IMPACT SENSOR 1 INTERNAL 1..............................176

VEHICLE BODY STYLE MISMATCH.......................................178

*AIRBAG INDICATOR ON WITHOUT ACTIVE TROUBLE CODES...............181

AUDIO

ALL CHANNELS SHORT TOGETHER OR TO GROUND ......................182

ALL INPUTS NO ACTIVITY ..............................................183

ALL OUTPUTS SHORT - PREMIUM AUDIO SYSTEM ........................185

ALL OUTPUTS SHORT- BASE AUDIO SYSTEM .............................187

CASSETTE PLAYER INOP ..............................................189

CD MECHANICAL FAILURE .............................................189

NO PCI TRANSMISSION ................................................189

*AM/FM SWITCH INOPERATIVE..........................................189

*ANY STATION PRESET SWITCH INOPERATIVE............................189

*BALANCE INOPERATIVE ...............................................189

*CD EJECT SWITCH INOPERATIVE.......................................189

*EQUALIZER INOPERATIVE .............................................189

*FADER INOPERATIVE .................................................189

*FF/RW SWITCH INOPERATIVE..........................................189

*HOUR/MINUTE SWITCHES INOPERATIVE ................................189

*PAUSE/PLAY SWITCH INOPERATIVE ....................................189

*PWR SWITCH INOPERATIVE ...........................................189

iii

TABLE OF CONTENTS - Continued

*SCAN SWITCH INOPERATIVE ..........................................189

*SEEK SWITCH INOPERATIVE...........................................189

*SET SWITCH INOPERATIVE ............................................189

*TAPE EJECT SWITCH INOPERATIVE.....................................189

*TIME SWITCH INOPERATIVE ...........................................189

*TUNE SWITCH INOPERATIVE...........................................189

CD PLAY FAILURE.....................................................191

CD READ FAILURE ....................................................192

CD TEMPERATURE HIGH...............................................193

DOOR AND/OR REAR CHANNELS SHORT TO GROUND.....................194

FRONT DOOR CHANNELS SHORT TOGETHER OR TO GROUND .............197

FRONT I/P CHANNELS SHORTED TOGETHER OR TO GROUND..............199

GPS ANTENNA NOT CONNECTED .......................................202

LEFT AND/OR RIGHT FRONT I/P AND DOOR CHANNEL SHORT TO GROUND . .203

LEFT FRONT DOOR AND LEFT REAR CHANNELS SHORT ACROSS...........206

LEFT FRONT DOOR AND RIGHT REAR CHANNELS SHORT ACROSS .........207

LEFT FRONT DOOR CHANNEL SHORT ACROSS ...........................208

LEFT FRONT I/P AND LEFT FRONT DOOR CHANNELS SHORTED ACROSS . . . .209

LEFT FRONT I/P AND LEFT REAR CHANNELS SHORT ACROSS..............210

LEFT FRONT I/P AND RIGHT FRONT DOOR CHANNELS SHORTACROSS .....211

LEFT FRONT I/P AND RIGHT REAR CHANNELS SHORT ACROSS.............212

LEFT FRONT I/P CHANNEL SHORT ACROSS ..............................213

LEFT FRONT INPUT NO ACTIVITY .......................................214

LEFT REAR CHANNEL SHORT ACROSS ..................................216

LEFT REAR INPUT NO ACTIVITY.........................................217

LOW VOLTAGE LEVEL .................................................219

NO ANTENNA CONNECTION ............................................220

PCI FAILURE..........................................................221

POWER AMP SHUTDOWN - BASE AUDIO SYSTEM .........................222

POWER AMP SHUTDOWN - PREMIUM AUDIO SYSTEM .....................224

RADIO AND NAV GPS ANTENNA NOT CONNECTED ........................226

REAR SPEAKERS SHORT TOGETHER OR TO GROUND ....................227

REMOTE RADIO SWITCH CIRCUIT HIGH..................................229

REMOTE RADIO SWITCH CIRCUIT STUCK ................................232

RIGHT FRONT DOOR AND LEFT REAR CHANNELS SHORT ACROSS .........235

RIGHT FRONT DOOR AND RIGHT REAR CHANNELS SHORT ACROSS ........236

RIGHT FRONT DOOR CHANNEL SHORT ACROSS..........................237

RIGHT FRONT I/P AND LEFT FRONT DOOR CHANNELS SHORTACROSS .....238

RIGHT FRONT I/P AND LEFT REAR CHANNELS SHORT ACROSS.............239

RIGHT FRONT I/P AND RIGHT FRONT DOOR CHANNELS SHORTACROSS . . . .240

RIGHT FRONT I/P AND RIGHT REAR CHANNELS SHORT ACROSS ...........241

RIGHT FRONT I/P CHANNEL SHORT ACROSS .............................242

RIGHT FRONT INPUT NO ACTIVITY ......................................243

RIGHT I/P SPEAKER AND BOTH REAR CHANNELS SHORT ACROSS..........245

RIGHT REAR CHANNEL SHORT ACROSS .................................246

RIGHT REAR INPUT NO ACTIVITY .......................................247

SOFTWARE CHECKSUM FAILURE .......................................249

*AMPLIFIER PRETEST .................................................250

CHIME

*CHIME INOPERATIVE..................................................251

*CHIME SOUNDS WITH DRIVER DOOR OPEN KEY REMOVED ...............252

*KEY IN IGNITION AND DRIVER’S DOOR OPEN CHIME INOPERATIVE.........253

TABLE OF CONTENTS - Continued

*VEHICLE SPEED WARNING CHIME PROBLEM ............................255

COMMUNICATION

FCM - BUS SHORTED TO BATTERY......................................256

FCM - BUS SHORTED TO GROUND ......................................256

FCM - EEPROM CHECKSUM FAILURE....................................257

FCM - INTERNAL BOOTLOADER CHECKSUM FAILURE .....................257

FCM - INTERNAL FLASH MEMORY CHECKSUM FAILURE ...................257

FCM - PCI BUS INTERNAL - LOOPBACK FAILURE ..........................257

FCM - MIC MESSAGES NOT RECEIVED ..................................258

FCM - PCM MESSAGES NOT RECEIVED..................................259

FCM - VIN NOT LEARNED CORRECTLY...................................261

*NO RESPONSE FROM AIRBAG CONTROL MODULE .......................262

*NO RESPONSE FROM AMPLIFIER ......................................264

*NO RESPONSE FROM COMPASS MINI-TRIP COMPUTER...................266

*NO RESPONSE FROM CONTROLLER ANTILOCK BRAKE ...................268

*NO RESPONSE FROM ECM (PCI BUS) - DIESEL ONLY .....................270

*NO RESPONSE FROM ECM (SCI ONLY) - DIESEL ONLY....................272

*NO RESPONSE FROM FRONT CONTROL MODULE ........................274

*NO RESPONSE FROM HANDS FREE MODULE............................276

*NO RESPONSE FROM HVAC ...........................................278

*NO RESPONSE FROM INSTRUMENT CLUSTER...........................280

*NO RESPONSE FROM PCM (PCI BUS) - JTEC ............................282

*NO RESPONSE FROM PCM (PCI BUS) - NGC.............................283

*NO RESPONSE FROM PCM (PCM SCI ONLY) - NGC .......................284

*NO RESPONSE FROM PCM (SCI ONLY) - JTEC ...........................287

*NO RESPONSE FROM RADIO ..........................................290

*NO RESPONSE FROM SENTRY KEY IMMOBILIZER MODULE ...............292

*NO RESPONSE FROM TRANSFER CASE CONTROL MODULE...............294

*NO RESPONSE FROM TRANSMISSION CONTROL MODULE ................296

*PCI BUS COMMUNICATION FAILURE ....................................299

COMPASS/MINI-TRIP COMPUTER

BUS MESSAGES MISSING ..............................................302

CMTC INTERNAL FAILURE..............................................303

DEMAGNETIZE COMPASS AS PER SERVICE MANUAL ......................304

FCM - AMBIENT TEMP CONFIGURATION ERROR ..........................305

FCM - AMBIENT TEMP SENSOR INPUT LOW ..............................306

FCM - AMBIENT TEMP SENSOR INPUT OPEN .............................308

SET COMPASS VARIANCE AS PER SERVICE INFORMATION.................310

*AVERAGE FUEL ECONOMY INACCURATE OR WRONG.....................311

*DISTANCE TO EMPTY INACCURATE OR WRONG..........................311

*ELAPSED IGNITION ON TIME INACCURATE OR WRONG ...................311

*TRIP ODOMETER INACCURATE OR WRONG .............................311

*CMTC OR EVIC INOPERATIVE ..........................................312

*COMPASS TEST FAILURE..............................................313

*TEMPERATURE DISPLAY INACCURATE OR INOPERATIVE..................314

DOOR AJAR

*DRIVER DOOR AJAR CIRCUIT OPEN ....................................315

*DRIVER DOOR AJAR CIRCUIT SHORTED TO GROUND.....................316

*LEFT REAR DOOR AJAR CIRCUIT OPEN .................................317

*LEFT REAR DOOR AJAR CIRCUIT SHORT TO GROUND ....................318

TABLE OF CONTENTS - Continued

*PASSENGER DOOR AJAR CIRCUIT SHORTED TO GROUND ................319

*PASSENGER DOOR AJAR CKT OPEN....................................320

*RIGHT REAR DOOR AJAR CIRCUIT OPEN................................321

*RIGHT REAR DOOR AJAR CIRCUIT SHORT TO GROUND...................322

ELECTRICALLY HEATED SYSTEMS

DEFOG RELAY CONTROL CKT SHORTED TO BATT ........................323

EXTERIOR LIGHTING

FCM-FRONT FOG LAMP RELAY OUTPUT CIRCUIT HIGH ....................325

FCM-FRONT FOG LAMP RELAY OUTPUT CIRCUIT LOW.....................326

FCM-FRONT FOG LAMP RELAY OUTPUT CIRCUIT OPEN....................327

FCM-FRONT LEFT TURN OUTPUT CIRCUIT LOW ..........................328

FCM-FRONT LEFT TURN OUTPUT CIRCUIT OPEN .........................329

FCM-FRONT RIGHT TURN OUTPUT CIRCUIT LOW .........................330

FCM-FRONT RIGHT TURN OUTPUT CIRCUIT OPEN ........................331

FCM-LEFT HIGHBEAM OUTPUT CIRCUIT LOW.............................332

FCM-LEFT HIGHBEAM OUTPUT CIRCUIT OPEN............................333

FCM-LEFT LOWBEAM OUTPUT CIRCUIT LOW .............................334

FCM-LEFT LOWBEAM OUTPUT CIRCUIT OPEN ............................335

FCM-LEFT STOP LAMP OUTPUT CIRCUIT LOW............................336

FCM-LEFT STOP LAMP OUTPUT CIRCUIT OPEN...........................337

FCM-LEFT TRAIL RELAY OUTPUT CIRCUIT HIGH ..........................338

FCM-LEFT TRAIL RELAY OUTPUT CIRCUIT LOW...........................339

FCM-LEFT TRAIL RELAY OUTPUT CIRCUIT OPEN..........................340

FCM-PARK LAMP RELAY OUTPUT CIRCUIT HIGH ..........................341

FCM-PARK LAMP RELAY OUTPUT CIRCUIT LOW...........................342

FCM-PARK LAMP RELAY OUTPUT CIRCUIT OPEN..........................343

FCM-REAR LEFT TURN OUTPUT CIRCUIT LOW............................344

FCM-REAR LEFT TURN OUTPUT CIRCUIT OPEN...........................345

FCM-REAR RIGHT TURN OUTPUT CIRCUIT LOW ..........................346

FCM-REAR RIGHT TURN OUTPUT CIRCUIT OPEN .........................347

FCM-RIGHT HIGHBEAM OUTPUT CIRCUIT LOW ...........................348

FCM-RIGHT HIGHBEAM OUTPUT CIRCUIT OPEN ..........................349

FCM-RIGHT LOWBEAM OUTPUT CIRCUIT LOW............................350

FCM-RIGHT LOWBEAM OUTPUT CIRCUIT OPEN...........................351

FCM-RIGHT STOP LAMP OUTPUT CIRCUIT LOW...........................352

FCM-RIGHT STOP LAMP OUTPUT CIRCUIT OPEN..........................353

FCM-RIGHT TRAIL RELAY OUTPUT CIRCUIT HIGH .........................354

FCM-RIGHT TRAIL RELAY OUTPUT CIRCUIT LOW..........................355

FCM-RIGHT TRAIL RELAY OUTPUT CIRCUIT OPEN.........................356

MIC-HEADLAMP SWITCH INPUT CIRCUIT OPEN ...........................357

MIC-HEADLAMP SWITCH INPUT CIRCUIT SHORTED .......................359

MIC-TURN HAZARD SWITCH INPUT CIRCUIT OPEN ........................360

MIC-TURN HAZARD SWITCH INPUT CIRCUIT SHORT.......................361

HEATING & A/C

A/C SWITCH FAULT (ACTIVE) ...........................................362

CHECKSUM FAILURE (ACTIVE)..........................................362

DEFOG SWITCH FAULT (ACTIVE) ........................................362

RECIRC SWITCH FAULT (ACTIVE) .......................................362

A/C SWITCH FAULT (STORED) ..........................................363

BACKLIGHT DIMMING RX FAILURE (STORED) .............................363

TABLE OF CONTENTS - Continued

BLEND OVERCURRENT (STORED).......................................363

CHECKSUM FAILURE (STORED).........................................363

DEFOG SWITCH FAULT (STORED).......................................363

ENGINE GAUGE RX FAILURE (STORED) ..................................363

EVAPORATOR TEMPERATURE SENSOR CIRCUIT OPEN (STORED)...........363

EVAPORATOR TEMPERATURE SENSOR CIRCUIT SHORTED (STORED).......363

LOOPBACK TEST FAILURE (STORED) ....................................363

MODE 1 OVERCURRENT (STORED)......................................363

MODE 2 OVERCURRENT (STORED)......................................363

PCM COMMUNICATION FAILURE (STORED)...............................363

RECIRC OVERCURRENT (STORED)......................................363

RECIRC SWITCH FAULT (STORED) ......................................363

REFRIGERANT PRESS RX FAILURE (STORED) ............................363

TX FAILURE (STORED) .................................................363

VIN RX FAILURE (STORED) .............................................363

ZONE OVERCURRENT (STORED)........................................363

ACT CKT TEST PASSED, OVERCURRENT DTCS ACTIVE ....................367

BLEND CIRCUIT SHORTED TO GROUND .................................367

BLEND CIRCUIT SHORTED TO IGN OR BATT..............................367

COMMON DRIVER SHORTED TO GROUND ...............................367

COMMON DRIVER SHORTED TO IGN OR BATT............................367

MODE 1 CIRCUIT SHORTED TO GROUND ................................367

MODE 1 CIRCUIT SHORTED TO IGN OR BATT.............................367

MODE 2 CIRCUIT SHORTED TO GROUND ................................367

MODE 2 CIRCUIT SHORTED TO IGN OR BATT.............................367

RECIRC CIRCUIT SHORTED TO GROUND.................................367

RECIRC CIRCUIT SHORTED TO IGN OR BATT.............................367

SHORT TOO COMPLEX ................................................367

ZONE CIRCUIT SHORTED TO GROUND ..................................367

ZONE CIRCUIT SHORTED TO IGN OR BATT...............................367

BACKLIGHT DIMMING RX FAILURE (ACTIVE) ..............................374

BLEND CALIBRATION FAULT ............................................376

MODE 1 CALIBRATION FAULT ...........................................376

MODE 2 CALIBRATION FAULT ...........................................376

RECIRCULATION CALIBRATION FAULT ...................................376

ZONE CALIBRATION FAULT .............................................376

BLEND OVERCURRENT (ACTIVE)........................................379

MODE 1 OVERCURRENT (ACTIVE).......................................379

MODE 2 OVERCURRENT (ACTIVE).......................................379

RECIRC OVERCURRENT (ACTIVE).......................................379

ZONE OVERCURRENT (ACTIVE).........................................379

BLOWER NOT ON HIGH ................................................381

COOLDOWN TEST SENSOR FAILURE ....................................382

COOLDOWN TIME EXCESSIVE FAULT....................................382

COOLDOWN TEST TOO COLD TO START .................................384

DEFOG RELAY CONTROL CKT SHORTED TO BATT ........................387

ENGINE GAUGE RX FAILURE (ACTIVE) ...................................388

PCM COMMUNICATION FAILURE (ACTIVE)................................388

REFRIGERANT PRESSURE RX FAILURE (ACTIVE) .........................388

VIN RX FAILURE (ACTIVE) ..............................................388

EVAPORATOR TEMPERATURE SENSOR CIRCUIT OPEN (ACTIVE)............390

EVAPORATOR TEMPERATURE SENSOR CIRCUIT SHORTED (ACTIVE)........392

LOOPBACK TEST FAILURE (ACTIVE) .....................................394

vii

TABLE OF CONTENTS - Continued

TX FAILURE (ACTIVE) ..................................................395

*A/C - HEATER CONTROL ILLUMINATION INOPERATIVE ....................397

*A/C STATUS INDICATOR FLASHING .....................................399

*EBL STATUS INDICATOR FLASHING .....................................399

*A/C STATUS INDICATOR WILL NOT ILLUMINATE -- A/C - HEATER CONTROL

WITHOUT EBL SW .....................................................401

*BLEND/MODE/RECIRC DOOR OPERATION IMPROPER -- DUAL-ZONE........402

*BLEND/MODE/RECIRC DOOR OPERATION IMPROPER -- SINGLE-ZONE ......405

*BLOWER MOTOR INOPERATIVE ........................................408

*BLOWER MOTOR SPEEDS INCORRECT .................................411

*HVAC SYSTEM TEST..................................................413

IGNITION, POWER, ACCESSORY

BATTERY 1 VOLTAGE OPEN ............................................415

BATTERY 2 VOLTAGE OPEN ............................................416

BATTERY VOLTAGE OPEN ..............................................417

HORN RELAY CONTROL CIRCUIT HIGH ..................................418

HORN RELAY CONTROL CIRCUIT LOW...................................419

HORN RELAY CONTROL CIRCUIT OPEN..................................419

IGNITION RUN/START MISMATCH........................................421

*HORNS INOPERATIVE.................................................422

INSTRUMENT CLUSTER

ABS INDICATOR OUTPUT CIRCUIT OPEN.................................425

ABS INDICATOR OUTPUT CIRCUIT SHORTED .............................425

AIRBAG WARNING INDICATOR OUTPUT CIRCUIT OPEN ....................425

AIRBAG WARNING INDICATOR OUTPUT CIRCUIT SHORT ...................425

MIL INDICATOR OUTPUT CIRCUIT OPEN .................................425

MIL INDICATOR OUTPUT CIRCUIT SHORTED..............................425

WAIT TO START INDICATOR OUTPUT CIRCUIT OPEN ......................425

WAIT TO START INDICATOR OUTPUT CIRCUIT SHORTED...................425

ABS MESSAGES NOT RECEIVED ........................................427

ACM MESSAGES NOT RECEIVED........................................427

FCM MESSAGES NOT RECEIVED........................................427

SKIM MESSAGES NOT RECEIVED .......................................427

TCCM MESSAGES NOT RECEIVED ......................................427

TCM MESSAGES NOT RECEIVED........................................427

BTSI OUTPUT CIRCUIT SHORTED OR OPEN ..............................429

INCORRECT ODOMETER VALUE FOUND .................................431

INTERNAL MODULE BOOTLOADER FAILURE ..............................432

INTERNAL MODULE FLASH MEMORY CHECKSUM FAILURE.................432

PCI BUS INTERNAL FAILURE............................................433

PCM MESSAGES NOT RECEIVED........................................434

PRNDL SWITCH INPUT CIRCUIT OPEN (DIESEL ONLY) .....................436

PRNDL SWITCH INPUT CIRCUIT SHORTED (DIESEL ONLY)..................438

VIN CHECKSUM ERROR................................................440

VIN PREVIOUSLY STORED..............................................440

*ALL GAUGES INOPERATIVE............................................441

*ANY PCI INDICATOR INOPERATIVE .....................................444

*BRAKE WARNING INDICATOR ALWAYS ON ...............................445

*BRAKE WARNING INDICATOR INOPERATIVE .............................447

*FUEL GAUGE INACCURATE ............................................449

*ONE GAUGE INOPERATIVE - GAS ENGINES..............................450

viii

TABLE OF CONTENTS - Continued

*PRNDL NOT DISPLAYING CORRECT POSITION (EATX VEHICLES) ...........451

*SEAT BELT WARNING INDICATOR ALWAYS OFF...........................452

*SEAT BELT WARNING INDICATOR ALWAYS OFF - STANDARD CAB ..........453

*SEAT BELT WARNING INDICATOR ALWAYS ON ...........................454

*SEAT BELT WARNING INDICATOR ALWAYS ON - STANDARD CAB ...........455

INTERIOR LIGHTING

MIC-CARGO LAMP OUTPUT CIRCUIT SHORTED OR OPEN ..................457

MIC-COURTESY-DOME LAMP OUTPUT CIRCUIT SHORTED OR OPEN ........458

MIC-GLOVE BOX-MAP LAMP OUTPUT CIRCUIT SHORT OR OPEN............459

POWER DOOR LOCKS/RKE

ALL DOOR LOCK OUTPUT CIRCUIT SHORT TO GROUND OR VOLTAGE.......460

ALL DOOR UNLOCK OUTPUT CIRCUIT SHORT TO GROUND OR VOLTAGE . . . .463

DRIVER CYLINDER LOCK SWITCH INPUT CIRCUIT SHORTED (WITH VTSS

ONLY) ...............................................................466

DRIVER CYLINDER LOCK SWITCH INPUT STUCK (WITH VTSS ONLY) ........468

DRIVER DOOR LOCK SWITCH INPUT CIRCUIT OPEN OR SHORT TO

VOLTAGE.............................................................469

DRIVER DOOR LOCK SWITCH INPUT CIRCUIT SHORTED...................471

DRIVER DOOR LOCK SWITCH INPUT CIRCUIT STUCK......................473

DRIVER DOOR UNLOCK OUTPUT CIRCUIT SHORT TO GROUND OR

VOLTAGE.............................................................474

PASSENGER DOOR LOCK SWITCH INPUT CIRCUIT OPEN OR SHORT TO

VOLTAGE.............................................................476

PASSENGER DOOR LOCK SWITCH INPUT CIRCUIT SHORTED ..............478

PASSENGER DOOR LOCK SWITCH INPUT CIRCUIT STUCK .................480

RKE FOB BATTERY LOW ...............................................481

RKE MODULE COMMUNICATION LINK....................................482

*ALL DOOR LOCKS INOPERATIVE .......................................483

*AUTO (ROLLING) DOOR LOCKS INOPERATIVE............................484

*CYLINDER LOCK SWITCH INOPERATIVE.................................485

*CYLINDER LOCK SWITCH WILL NOT ARM AND/OR DISARM ALARM .........485

*DOOR LOCK INHIBIT INOPERATIVE .....................................487

*LEFT DOORS FAIL TO LOCK AND UNLOCK - QUAD CAB ...................488

*ONE DOOR LOCK MOTOR INOPERATIVE ................................490

*RIGHT DOORS FAIL TO LOCK AND UNLOCK - QUAD CAB ..................491

*RKE INOPERATIVE....................................................493

TELECOMMUNICATION

AUDIO HARDWARE MESSAGE NOT RECEIVED............................495

BLUETOOTH ERROR...................................................496

FLASH CHECKSUM ERROR.............................................496

FLASH WRITE ERROR .................................................496

PCI BUS INTERNAL ERROR.............................................496

RAM WRITE ERROR ...................................................496

ROM CHECKSUM ERROR ..............................................496

BODY STYLE MESSAGE NOT RECEIVED .................................498

INVALID BODY STYLE..................................................498

GENERAL MICROPHONE FAULT.........................................499

IGNITION POWER MESSAGE NOT RECEIVED .............................501

LEFT AUDIO INPUT SHORT TO GROUND .................................502

LEFT AUDIO INPUT SHORT TO VOLTAGE .................................502

TABLE OF CONTENTS - Continued

LEFT AUDIO OUTPUT 1 SHORT TO GROUND..............................502

LEFT AUDIO OUTPUT 1 SHORT TO VOLTAGE .............................502

MIRROR POWER CIRCUIT SHORT TO GROUND ...........................505

MIRROR POWER CIRCUIT SHORT TO VOLTAGE...........................505

PCI BUS BUSY ........................................................507

PCI BUS CIRCUIT OPEN................................................507

PCI BUS CIRCUIT SHORT TO GROUND...................................507

PCI BUS CIRCUIT SHORT TO VOLTAGE ..................................507

PHONE SWITCH STUCK................................................509

VOICE RECOGNITION SWITCH STUCK ...................................509

VOICE RECOGNITION/PHONE SWITCH CIRCUIT RATIONALITY ..............509

VOICE RECOGNITION/PHONE SWITCH CIRCUIT SHORT TO GROUND ........509

VOICE RECOGNITION/PHONE SWITCH CIRCUIT SHORT TO VOLTAGE........509

PRNDL MESSAGE NOT RECEIVED.......................................513

RADIO MESSAGE NOT RECEIVED .......................................514

RIGHT AUDIO INPUT SHORT TO GROUND ................................515

RIGHT AUDIO INPUT SHORT TO VOLTAGE................................515

RIGHT AUDIO OUTPUT 1 SHORT TO GROUND ............................515

RIGHT AUDIO OUTPUT 1 SHORT TO VOLTAGE ............................515

RPM MESSAGE NOT RECEIVED.........................................518

VIN MESSAGE NOT RECEIVED..........................................519

VIN MISMATCH........................................................520

VEHICLE THEFT/SECURITY

*ALARM TRIPS ON ITS OWN ............................................521

*DRIVER DOOR DOES NOT TRIP VTSS ...................................522

*HEADLAMPS FAIL TO FLASH WHEN ALARM IS TRIPPED ...................523

*HORN FAILS TO SOUND WHEN ALARM IS TRIPPED .......................524

*LEFT REAR DOOR DOES NOT TRIP VTSS (4 DOOR).......................525

*PASSENGER DOOR DOES NOT TRIP VTSS ..............................526

*RIGHT REAR DOOR DOES NOT TRIP VTSS (4 DOOR) .....................527

*VTSS WILL NOT ARM PROPERLY .......................................528

WINDSHIELD WIPER & WASHER

FCM-WASHER FLUID LEVEL SENSOR CIRCUIT FAILURE....................530

FCM-WASHER PUMP OUTPUT CIRCUIT LOW..............................532

FCM-WASHER PUMP OUTPUT CIRCUIT OPEN.............................534

FCM-WIPER ON-OFF RELAY OUTPUT CIRCUIT HIGH.......................536

FCM-WIPER ON-OFF RELAY OUTPUT CIRCUIT LOW .......................537

FCM-WIPER ON-OFF RELAY OUTPUT CIRCUIT OPEN ......................538

FCM-WIPER PARK SWITCH INPUT PERFORMANCE ........................539

FCM-WIPER SPEED RELAY OUTPUT CIRCUIT HIGH........................541

FCM-WIPER SPEED RELAY OUTPUT CIRCUIT LOW ........................542

FCM-WIPER SPEED RELAY OUTPUT CIRCUIT OPEN .......................543

MIC-WASH-BEAM INPUT CIRCUIT SHORTED ..............................544

MIC-WIPER SWITCH INPUT CIRCUIT OPEN ...............................546

MIC-WIPER SWITCH INPUT CIRCUIT SHORTED ...........................548

VERIFICATION TESTS

VERIFICATION TESTS..................................................550

TABLE OF CONTENTS - Continued

8.0 COMPONENT LOCATIONS..............................................557

8.1 AIRBAG SYSTEM.................................................557

8.2 AUDIO ..........................................................558

8.2.1 AMPLIFIER ..............................................558

8.3 HEATING & A/C...................................................558

8.4 INSTRUMENT CLUSTER...........................................559

8.5 POWER DOOR LOCKS/RKE........................................559

8.5.1 CYLINDER LOCK SWITCH .................................559

8.5.2 RKE MODULE............................................559

9.0 CONNECTOR PINOUTS ................................................561

A/C HEATER CONTROL C1 - BLACK 16 WAY ..............................561

A/C HEATER CONTROL C2 - BLACK 10 WAY ..............................561

AIRBAG CONTROL MODULE C1 - 24 WAY.................................562

AIRBAG CONTROL MODULE C2 - 32 WAY.................................563

AIRBAG-DRIVER SQUIB 1 - (SENSOR SIDE)...............................563

AIRBAG-DRIVER SQUIB 2 - (SENSOR SIDE)...............................564

AIRBAG-LEFT CURTAIN - YELLOW 2 WAY.................................564

AIRBAG-PASSENGER ON/OFF SWITCH-6WAY...........................564

AIRBAG-PASSENGER SQUIB-4WAY....................................564

AIRBAG-RIGHT CURTAIN - YELLOW 2 WAY ...............................565

AMBIENT TEMPERATURE SENSOR-2WAY...............................565

AMPLIFIER AUDIO C1 (PREMIUM) - GRAY 12 WAY .........................565

AMPLIFIER AUDIO C2 (PREMIUM) - GRAY 18 WAY .........................566

AUTOMATIC DAY/NIGHT MIRROR C1 (EXCEPT BASE)-7WAY...............566

AUTOMATIC DAY/NIGHT MIRROR C2 (TELEMATICS) - 12 WAY ...............566

BLEND DOOR ACTUATOR (SINGLE ZONE)-2WAY.........................567

BLOWER MOTOR - BLACK 2 WAY........................................567

BLOWER MOTOR RESISTOR BLOCK - BLACK 4 WAY.......................567

BRAKE TRANSMISSION SHIFT INTERLOCK SOLENOID - BLACK 2 WAY .......567

C200 - (HVAC SIDE)....................................................568

C200 - (I/P SIDE) ......................................................568

C201 - WHITE (HEADLINER SIDE)........................................568

C201 - WHITE (I/P SIDE)................................................569

C219 - (HEADLAMP AND DASH SIDE) ....................................570

C219 - (I/P SIDE) ......................................................571

C220 - (I/P SIDE) ......................................................572

C220 - NATURAL (BODY SIDE) ..........................................572

C308 - (BODY SIDE) ...................................................573

C308 - (I/P SIDE) ......................................................573

CLOCKSPRING C1-6WAY.............................................573

CLOCKSPRING C2 - YELLOW 4 WAY .....................................574

CLOCKSPRING C3 - BLACK 4 WAY.......................................574

CLOCKSPRING C4-2WAY.............................................574

COMPASS/MINI-TRIP COMPUTER (EXCEPT BASE) - BLACK 6 WAY ...........574

CONTROLLER ANITLOCK BRAKE C1 - BLACK 14 WAY ......................575

CYLINDER LOCK SWITCH-DRIVER (PREMIUM)-2WAY.....................575

DATA LINK CONNECTOR - BLACK 16 WAY ................................575

DOME LAMP - BLACK 3 WAY............................................576

DOOR AJAR SWITCH-DRIVER - BLACK 2 WAY.............................576

DOOR AJAR SWITCH-LEFT REAR - BLACK 2 WAY..........................576

TABLE OF CONTENTS - Continued

DOOR AJAR SWITCH-PASSENGER - BLACK 2 WAY ........................576

DOOR AJAR SWITCH-RIGHT REAR - BLACK 2 WAY ........................576

DOOR LOCK MOTOR/AJAR SWITCH-DRIVER - BLACK 4 WAY................577

DOOR LOCK MOTOR/AJAR SWITCH-LEFT REAR - BLACK 4 WAY.............577

DOOR LOCK MOTOR/AJAR SWITCH-PASSENGER - BLACK 4 WAY ...........577

DOOR LOCK MOTOR/AJAR SWITCH-RIGHT REAR - BLACK 4 WAY ...........577

DOOR LOCK SWITCH-PASSENGER-6WAY...............................578

DRIVER BLEND DOOR ACTUATOR (DUAL ZONE) ..........................578

DRIVER DOOR MODULE C1 - BLUE 12 WAY...............................578

DRIVER DOOR MODULE C2 - BLUE 8 WAY................................578

ENGINE CONTROL MODULE C2 (DIESEL) - 50 WAY ........................579

EVAPORATOR TEMPERATURE SENSOR-2WAY..........................580

FOG LAMP-LEFT - GRAY 2 WAY .........................................580

FOG LAMP-RIGHT - WHITE 2 WAY .......................................580

GLOVE BOX LAMP AND SWITCH - BLACK 2 WAY ..........................580

HANDS FREE MODULE (TELEMATICS) - 22 WAY ...........................581

HEADLAMP SWITCH - BLACK 8 WAY.....................................581

HEADLAMP-LEFT - BLUE 3 WAY .........................................581

HEATED MIRROR RELAY - 5 WAY........................................583

HORN SWITCH - WHITE 2 WAY..........................................583

HORN-HIGH NOTE-2WAY.............................................583

HORN-LOW NOTE-2WAY..............................................583

IGNITION SWITCH - BLACK 14 WAY......................................584

INSTRUMENT CLUSTER C1 - WHITE 26 WAY..............................584

INSTRUMENT CLUSTER C2 - GRAY 16 WAY...............................585

INSTRUMENT CLUSTER C3 - GRAY 26 WAY...............................585

INTEGRATED POWER MODULE (FCM) - 49 WAY ...........................587

FOG LAMP RELAY .....................................................590

HORN RELAY .........................................................590

WIPER HIGH/LOW RELAY...............................................590

PARK LAMP RELAY ....................................................590

TRAILER TOW LEFT TURN RELAY .......................................590

TRAILER TOW RIGHT TURN RELAY......................................590

WIPER ON/OFF RELAY .................................................590

INTEGRATED POWER MODULE C1 - 26 WAY..............................591

INTEGRATED POWER MODULE C2 - WHITE 15 WAY .......................591

INTEGRATED POWER MODULE C3 - 16 WAY..............................592

INTEGRATED POWER MODULE C4 - 10 WAY..............................592

INTEGRATED POWER MODULE C5 - 26 WAY..............................593

INTEGRATED POWER MODULE C7 - GRAY 26 WAY ........................594

MODE DOOR ACTUATOR 1 (PANEL TO FLOOR)-2WAY....................594

MODE DOOR ACTUATOR 2 (DEFROST TO FLOOR)-2WAY.................594

MULTI-FUNCTION SWITCH - BLACK 4 WAY................................595

PARK/TURN SIGNAL LAMP-LEFT FRONT - BROWN 3 WAY...................595

PASSENGER BLEND DOOR ACTUATOR (DUAL-ZONE)-2WAY...............595

POWERTRAIN CONTROL MODULE C1 (NGC) - BLACK 38 WAY...............596

RADIO C1 (EXCEPT INFINITY) - GRAY 22 WAY.............................597

RADIO C1 (INFINITY) - GRAY 22 WAY.....................................597

RADIO C2 - 10 WAY....................................................598

REAR WINDOW DEFOGGER RELAY......................................600

RECIRCULATION DOOR ACTUATOR-2WAY..............................600

REMOTE RADIO SWITCH-LEFT - BLACK 2 WAY............................600

REMOTE RADIO SWITCH-RIGHT - BLACK 2 WAY...........................600

xii

TABLE OF CONTENTS - Continued

SEAT BELT TENSIONER REDUCER (STANDARD CAB)-2WAY...............600

SEAT BELT TENSIONER-DRIVER-2WAY.................................601

SEAT BELT TENSIONER-PASSENGER-2WAY.............................601

SENTRY KEY IMMOBILIZER MODULE (SKIM) - BLACK 6 WAY................601

SIDE IMPACT SENSOR-LEFT - 4 WAY ....................................601

SIDE IMPACT SENSOR-RIGHT - 4 WAY ...................................601

SPEAKER-CENTER INSTRUMENT PANEL - 2 WAY..........................602

SPEAKER-LEFT FRONT DOOR - WHITE 3 WAY ............................602

SPEAKER-LEFT INSTRUMENT PANEL - BLACK 2 WAY ......................602

SPEAKER-LEFT REAR - WHITE 3 WAY....................................602

SPEAKER-RIGHT FRONT DOOR - WHITE 3 WAY ...........................603

SPEAKER-RIGHT INSTRUMENT PANEL - BLACK 2 WAY.....................603

SPEAKER-RIGHT REAR - WHITE 3 WAY ..................................603

TRANSFER CASE CONTROL MODULE C1 (ELECTRIC 4x4) - 16 WAY..........603

TRANSFER CASE CONTROL MODULE C2 (ELECTRIC 4x4) - 16 WAY..........604

TRANSFER CASE CONTROL MODULE C3 (ELECTRIC 4x4)-4WAY...........604

WIPER MOTOR-4WAY................................................604

10.0 SCHEMATIC DIAGRAMS................................................605

10.1 AIRBAG SYSTEM .................................................605

10.2 AUDIO SYSTEM ..................................................606

10.2.1 PREMIUM AUDIO SYSTEM .................................606

10.2.2 BASE AUDIO SYSTEM.....................................607

10.2.3 REMOTE RADIO CONTROLS...............................608

10.3 COMMUNICATION ................................................609

10.3.1 PCI BUS COMMUNICATION ................................609

10.3.2 PCM COMMUNICATION - JTEC .............................610

10.3.3 PCM COMMUNICATION - NGC..............................610

10.3.4 ECM COMMUNICATION - DIESEL ...........................611

10.4 DOOR AJAR SYSTEM .............................................612

10.5 ELECTRICALLY HEATED SYSTEMS .................................613

10.5.1 HEATED MIRROR SYSTEM ................................613

10.5.2 REAR WINDOW DEFOGGER ...............................614

10.6 EXTERIOR LIGHTS ...............................................615

10.7 HEATING A/C SYSTEM ............................................616

10.8 IGNITION, POWER, ACCESSORY ...................................617

10.8.1 HORN SYSTEM ..........................................617

10.9 INSTRUMENT CLUSTER...........................................618

10.10 OVERHEAD CONSOLE ............................................619

10.11 POWER DOOR LOCKS ............................................620

10.12 TELECOMMUNICATIONS - HANDS FREE SYSTEM ....................621

10.13 VEHICLE THEFT SECURITY SYSTEM................................622

10.14 WIPERS.........................................................623

11.0 CHARTS AND GRAPHS ................................................625

11.1 DIAGNOSTIC TROUBLE CODE .....................................625

xiii

NOTES

xiv

GENERAL INFORMATION

1.0 INTRODUCTION

The procedures contained in this manual include all the specifications, instructions and graphics needed todiagnose2004 body system problems.The diagnostics in this manual are based on the failure condition or symptom being present at the time of diagnosis.

Please follow the recommendations below when choosing your diagnostic path.

1. First make sure the DRBIIIt is communicating

with the appropriate modules; i.e., if the DRBIIIt displays a “No Response” or a “Bus 6 Signals Open” condition, you must diagnose that first.

2. Read DTC’s (diagnostic trouble codes) with the

DRBIIIt.

3. If no DTC’s are present, identify the customer

complaint.

4. Once the DTC or customer complaint is identi-

fied, locate the matching test in the Table of

Contents and begin to diagnose the symptom. All component location views are in Section 8.0. All connector pinouts are in Section 9.0. All schematics are in Section 10.0. An * placed before the symptom description indicates a customer complaint.

When repairs are required, refer to the appropriate service information for the proper removal and repair procedure.

Diagnostic procedures change every year. New diagnostic systems may be added: carryover systems may be enhanced. READ THIS MANUAL BEFORE TRYING TO DIAGNOSE A VEHICLE DIAGNOSTIC TROUBLE CODE. It is recommended that you review the entire manual to become familiar with all the new and changed diagnostic procedures.

This book reflects many suggested changes from readers of past issues. After using this book, if you have any comments or suggestions, please fill out the form in the back of this book and mail it back to us.

1.1 SYSTEM COVERAGE

This diagnostic procedures manual covers all 2004 DR Ram Truck vehicles.

1.2 SIX-STEP TROUBLESHOOTING

PROCEDURE

Diagnosis of the body system is done in six basic steps:

• verification of complaint

• verification of any related symptoms

• symptom analysis

• problem isolation

• repair of isolated problem

• verification of proper operation

2.0 IDENTIFICATION OF SYSTEM

The vehicle systems that are part of the “body”

system are:

• Airbag

• Audio (with amplifier on premium systems)

• Chime

• Communication

• Door Ajar System

• Electrically heated system

• Exterior lighting

• Heating and A/C

• Horn

• Instrument Cluster

• Interior Lighting

• Memory Seat

• Overhead Console

• Power Door Lock/RKE

• Power windows

• Telecommunications (hands free phone)

• Vehicle theft security system (VTSS)

• Windshield Wiper and Washer

3.0 SYSTEM DESCRIPTION AND FUNCTIONAL OPERATION

The body system on the 2004 DR consists of a combination of modules that communicate over the PCI bus (Programmable Communication Interface multiplex system). Through the PCI bus, information about the operation of vehicle components and circuits is relayed quickly to the appropriate module(s).All modules receiveallthe information transmitted on the bus even though a module may not require all information to perform its function. It will only respond to messages “addressed” to it through binary coding process. This method of data transmission significantly reduces the complexity of the wiring in the vehicle and the size of wiring harnesses. All of the information about the functioning of all the systems is organized, controlled, and communicated by the PCI bus, which is described inthecommunicationsection of this general information.

GENERAL INFORMATION

3.1 AIRBAG SYSTEM

The airbag system is designed to provide increased driver and passenger protection if the vehicle is involved in a front end or side collisions. The system is most effective when used in conjunction with the seat belt system.

On some models the ACM supports Seat Belt Tensioners, Passenger Airbag Off Switch, and others Impact Sensor. It may be necessary to use the DRBIIIt to reconfigure the ACM to the vehicle equipment.

The airbag control module (ACM) is an electronic module that monitors the airbag system for proper operation, stores diagnostic trouble code (DTCs), controls the airbag warning lamp and contains the sensor and actuator that is responsible for driver, passenger, and curtain airbag deployment. The ACM is mounted on a special bracket that is fastened to the floor of the truck at the bottom of the instrument panel. It is located forward of the console. The ACM provides diagnostic information (DTCs) to the technician through the DRBIIIt via the PCI bus. Some circuits are tested continuously; others are checked only under certain circumstances. The warning lamp is driven with messages relayed to the Electro/Mechanical Instrument Cluster (EMIC) from the ACM via the PCI bus.

The AIRBAG warning lamp is the only point at which “symptoms” of a system malfunction can be observed by the customer. Whenever the ignition key is turned to the “run” position, the airbag control module performs a lamp check by turning theAIRBAG warning lamp on for 6-8seconds.If the lamp remains off, it means that the ACM has checked the system and found it to be free of discernible malfunctions. If the lamp remains on, there could be an active fault in the system or the circuit that operates the lamp may be shorted to ground. If the lamp comes on and stays on for a period longer than 6-8 seconds, then goes off, there is usually an intermittent problem in the system.

WARNING: THE AIRBAG CONTROL MODULE CONTAINS THE IMPACT SENSOR, WHICH ENABLES THE SYSTEM TO DEPLOY THE AIRBAG. BEFORE ATTEMPTING TO DIAGNOSE OR SERVICE ANY AIRBAG SYSTEM OR RELATED STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENTS YOU MUST FIRST DISCONNECT AND ISOLATE THE BATTERY NEGATIVE (GROUND) CABLE. THEN WAIT TWO MINUTES FOR THE SYSTEM CAPACITOR TO DISCHARGE BEFORE FURTHER SYSTEM SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE

TO DO THIS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY OR DEATH.

WARNING: NEVER STRIKE OR KICK THE AIRBAG CONTROL MODULE, AS IT CAN DAMAGE THE IMPACT SENSOR OR AFFECT ITS CALIBRATION. IF AN AIRBAG CONTROL MODULE IS ACCIDENTALLY DROPPED DURING SERVICE, THE MODULE MUST BE SCRAPPED AND REPLACED WITH A NEW UNIT. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND PERSONAL INJURY OR DEATH.

The DR will have two Airbag Control Modules. Each ACM is specifically calibrated for one body type, light duty or heavy duty. To determine the body types the ACM monitors the PCI Bus for a message containing the complete VIN. The ACM uses the 6th digit of the VIN to identify the heavy duty or light duty vehicle. The 6th digit of the VIN will be a number 1 for light-duty vehicle and a 2, 3 or 4 for heavy-duty vehicle. If the PCI Bus VIN message 6th character matches theACM body type, the VIN will be stored within 5.6 seconds after ignition on. After the VIN is stored, the ACM verifies PCI Bus VIN message within 2.6 seconds after the ignition is turned on.

If two valid matching PCI Bus VIN messages are not received within 5.6 seconds the ACM will set a Missing Original VIN DTC.

If theACMand PCM module types, 6th character of the VIN, light-duty or heavy-duty do not match the Calibration Mismatch DTC will be set.

CAUTION: Therefore, the practice ofexchanging (swapping) airbag control modules, instrument clusters, powertrain control modules and other electronic modules in this vehicle with those removed from another vehicle must always be avoided.

3.1.1 DRIVER AIRBAG

The airbag protective trim cover is the most visible part of the driver side airbag system. The protective trim cover is fitted to the front of the airbag module and forms a decorative cover in the center of the steering wheel. The module is mounted directly to the steering wheel. Located under the trimcoverare the horn switch, the airbag cushion, and the airbag cushion supporting components. The airbag module includes a housing to which the cushion and hybrid inflator are attached and sealed. The airbag module cannot be repaired, and must be replaced if deployed or in any way damaged.

GENERAL INFORMATION

3.1.2 CLOCKSPRING

The clockspring is mounted on the steering column behind the steering wheel. This assembly consist of a plastic housing which contains a flat, ribbon-like, electrically conductive tape that winds and unwinds with the steering wheel rotation. The clockspring is used to maintain a continuous electrical circuit between the instrument panel wiring and the driver airbag, the horn, and the vehicle speed control switches if equipped. The clockspring must be properly centered when it is reinstalled on the steering column following any service procedure, or it could be damaged. The clockspring cannot be repaired and it must be replaced.

3.1.3 PASSENGER AIRBAG

When supplied with the proper electrical signal the passenger airbag inflator or inflators discharge the gasdirectlyintothe cushion. The airbag module cannot be repaired, and must be replaced if deployed or in any way damaged.

WARNING: THE PASSENGER AIRBAG MODULE CONTAINSARGON GAS PRESSURIZED TO 17236.89 Kpa (2500 PSI). DO NOT ATTEMPT TO DISMANTLE AN AIRBAG MODULE OR TAMPER WITH ITS INFLATOR. DO NOT PUNCTURE, INCINERATE, OR BRING INTO CONTACT WITH ELECTRICITY. DO NOT STORE AT TEMPERATURE EXCEEDING 93°C (200°F). REPLACE AIRBAG SYSTEM COMPONENTS ONLY WITH PARTS SPECIFIED IN THE MOPAR PARTS CATALOG. SUBSTITUTE PARTS MAY APPEAR INTERCHANGEABLE,BUTINTERNALDIFFERENCES MAY RESULT IN INFERIOR OCCUPANT PROTECTION. THE FASTENERS, SCREWS, AND BOLTS ORIGINALLY USED FOR THE AIRBAG SYSTEM COMPONENTS HAVE SPECIAL COATINGS AND ARE SPECIFICALLY DESIGNED FOR THE AIRBAG SYSTEM. THEY MUST NEVER BE REPLACED WITH ANY SUBSTITUTES. ANY TIME A NEW FASTENER IS NEEDED, REPLACE IT WITH THE CORRECT FASTENERS PROVIDED IN THE SERVICE PACKAGE OR SPECIFIED IN THE MOPAR PARTS CATALOG. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND PERSONAL INJURY OR DEATH.

3.1.4 PASSENGER AIRBAG ON-OFF SWITCH

The Passenger Airbag On-Off Switch allows the customer to turn the passenger airbag function ON or OFF. The OFF indicator will be illuminated whenever the switch is turned to the off position and for2secondsat ignition on for anindicatorbulb test. The switch assembly is mounted in the center of instrument panel to make the OFF indicator visible to all front seat occupants.

WARNING: TOAVOID PERSONAL INJURY OR DEATH, ALWAYS CHECK THE PASSENGER AIRBAG ON-OFF SWITCH POSITION BEFORE DRIVING THE VEHICLE. A SWITCH IN THE WRONG POSITION INCREASES THE RISK OF SERIOUS INJURY OR DEATH IN A COLLISION.

To operate, insert the ignition key into the switch keyhole, pushkeyinto release the internal plunger, and rotate to the desired switch position. The spring-loaded locking plunger prevents the user from leaving the key in the switch. The key will be automatically ejected whenforceisnot applied. The ignition key is the only key or object that should ever be inserted into the switch.

NOTE: Do not turn the On-Off switch with the ignition on.

TheACM continuously monitors the resistance of the Passenger Airbag On-Off Switch circuits to identify the switch position and provide circuit diagnostics. The on-off switch ON position resistance is 175 to 190 ohms and the OFF position resistance is 820 to 870 ohms. If the on-off switch circuits are open, shorted to ground or battery the ACM will set active and stored DTC. Upon receiving a switch diagnostic trouble code the airbag warning indicator, in the instrument cluster, will be turned on by the ACM. Whenever the airbag warning indicator is illuminated, theACM should be the first module interrogated.

GENERAL INFORMATION

WARNING: IGNORING THE AIRBAG WARNING LIGHT IN YOUR INSTRUMENT PANEL COULD MEAN THE PASSENGER AIRBAG ON-OFF SWITCH IS NOT FUNCTIONAL AND THE AIRBAG MAY DEPLOY IF AN IMPACT OCCURS. IF THE AIRBAG WARNING LIGHT TURNS ON WHILE DRIVING, THE AIRBAG ON-OFF SWITCH SETTING WILL REMAIN FUNCTIONAL FOR THAT KEY CYCLE. IF THE AIRBAG WARNING LIGHT COMES ON AGAIN AT THE NEXT KEY ON AND STAYS LIT FOR MORE THAN 6-8 SECONDS, THE ACM WILL DEFAULT TO PASSENGER AIRBAG ON. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND PERSONAL INJURY OR DEATH.

3.1.5 SEAT BELT TENSIONER

Front seat belt systems incorporate Tensioner Modules (SBT).At theonsetof an impact eventeach tensioner uses a pyrotechnic device, which is triggered simultaneously with the airbags, to rapidly retract the seat belts. With the slack removed, the occupant’s forward motion in an impact will be reduced as will the likelihood of contacting interior components. After an impact that deploys the airbag, the seat belt tensioner assembly must be replaced.

TheACM module monitors the Seat Belt Tensioners circuit resistance and reports active and stored DTC’s if any problem is found.

3.1.6 SIDE IMPACT SENSORS

The side impact sensors are electronic accelerometers that sense the rate of vehicle deceleration and when combined with the ACM Accelerometer provides verification of the direction and severity of a side impact. Each sensor also contains an electronic communication chip that allows the unit to communicate the sensor status as well as sensor fault information to the microprocessor in the Airbag Control Module. The ACM microprocessor continuously monitors all of the passive restraint system electrical circuits to determine the system readiness. If the ACM detects a system fault, it sets a Diagnostic Trouble Code and controls the airbag warning indicator operation accordingly. The side impact sensors receive battery current and ground through dedicated driver and passenger sensor signal and ground circuits from the ACM. The impact sensors and the ACM communicate by modulating the current inthesensor signal circuit. If the sensor is dropped it must be replaced. Disconnect the battery or removebothairbag fuses before servicing impact sensors.

CAUTION: Do not remove or install the impact sensors while the sensor is attached to the vehicle wiring.

3.1.7 CURTAIN AIRBAGS

The Left and Right curtain airbags are located in the outboard edge of the roof under the headliner, just above the door openings. When supplied with the proper electrical signal the inflator can discharge the compress gas directly into the curtain airbag. Upon deployment,thecurtain will tear open the headliner allowing the curtain airbag to fully deploy between the headliner and seat. The curtain airbag cannot be repaired and must be replaced if deployed or in any way damaged.

WARNING: THE CURTAIN AIRBAG CONTAINS AN INERT GAS PRESSURIZED TO

17236.89 Kpa (2500 PSI). DO NOT ATTEMPT TO DISMANTLE AN AIRBAG MODULE OR TAMPER WITH ITS INFLATOR.DONOT PUNCTURE, INCINERATE, OR BRING INTO CONTACT WITH ELECTRICITY. DO NOT STORE AT TEMPERATURE EXCEEDING 93°C (200°F). REPLACE AIRBAG SYSTEM COMPONENTS ONLY WITH PARTS SPECIFIED IN THE CHRYSLER MOPAR PARTS CATALOG. SUBSTITUTE PARTS MAY APPEAR INTERCHANGEABLE, BUT INTERNAL DIFFERENCES MAY RESULT IN INFERIOR OCCUPANT PROTECTION. THE FASTENERS, SCREWS, AND BOLTS ORIGINALLY USED FOR THE AIRBAG SYSTEM COMPONENTS HAVE SPECIAL COATINGS AND ARE SPECIFICALLY DESIGNED FOR THE AIRBAG SYSTEM. THEY MUST NEVER BE REPLACED WITH ANY SUBSTITUTES. ANY TIME A NEW FASTENER IS NEEDED, REPLACE IT WITH THE CORRECT FASTENERS PROVIDED IN THE SERVICE PACKAGE OR SPECIFIED IN THE MOPAR PARTS CATALOG. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND PERSONAL INJURY OR DEATH.

3.1.8 SPECIAL TOOLS

Some airbag diagnostic test use special tools, airbag load tools, 8310 and 8443 for testing squib circuits. The load tools contain fixed resistive loads, jumpers and adapters. The fixed loads are connected to cables and mounted in a storage case. The cables can be directly connected to some airbag system connectors. Jumpers are used to convert the load tool cable connectors to the other airbag system connectors. The adapters are connected to the

GENERAL INFORMATION

module harness connector to open shorting clips and protect the connector terminal during testing. When using the load tool follow all of the safety procedures in the service information for disconnecting airbag system components. Inspect the wiring, connector and terminals for damage or misalignment. Substitute the airbag load tool in place of an Driver or Passenger Airbag, curtain airbag, clockspring, or seat belt tensioner (use a jumper if needed). Then follow all of the safety procedures in the service information for connecting airbag system components. Read the module active DTC’s. If the modulereportsNO ACTIVEDTC’sthe defective component has been removed from the system and should be replaced. If the DTC is still active, continue this process until all component in the circuit have been tested. Then disconnect the module connector and connect the matching adapter to the module connector. With all airbags disconnected and the adapter installed the squib wiring can be tested for open and shorted conditions.

3.1.9 AIRBAG DIAGNOSTIC TROUBLE CODES

Airbag diagnostic trouble codes consist of active and stored codes. If more than one code exists, diagnostic priority should be given to the active codes.

Each diagnostic trouble code is diagnosed by following a specific testing procedure. The diagnostic test procedurescontainstep-by-step instructions for determining the cause of the trouble codes. It is not necessary to perform all of the tests in this book to diagnose an individual code.

Always begin by reading the diagnostic trouble codes using the DRBIIIt.

Active diagnostic trouble codes for the airbag system are not permanent and will change the moment the reason for the code is corrected. In certain test procedures within this manual, diagnostic trouble codes are used as a diagnostic tool.

3.1.9.1 ACTIVE CODES

The code becomes active as soon as the malfunction is detected and stored after one minute of occurrence or key-off, whichever occurs first. An active trouble code indicates an on-going malfunction. This means that the defect is currently there every time the airbag control module checks that circuit/function. It is impossible to erase an active code; active codes automatically erase by themselves when the reason for the code has been corrected.

With the exception of the warning lamp trouble codes or malfunctions, when a malfunction is de-

tected, the airbag lamp remains lit for a minimum of 12 seconds or as long as the malfunction is present.

3.1.9.2 STORED CODES

Airbag codes are automatically stored in the ACM’s memory after one minute of occurrence or when the ignition is turned off. The exception is the “Loss of Ignition Run Only” code which is an active code only.

A“stored”codeindicatesthere was an active code present at some time. However, the code currently may not be present as an active code, although another active code could be.

When atroublecode indicates there wasanactive code present at some time. However, the code currently may not be present as an active code, although another active code could be.

The minimum time shown for any code will be one minute, even if the code was actually present for less than one minute. Thus, the time shown for a code that was present for two minutes 13 seconds, for example, would be three minutes.

If a malfunction is detected a diagnostic trouble code is stored and will remain stored. When and if the malfunction ceases to exist, an ignition cycle count will be initiated for that code. If the ignition cycle count reaches 100 without a reoccurrence of the same malfunction, that diagnostic trouble code is erased and that ignition cycle counter is reset to zero. If the malfunction reoccurs before the count reaches 100, then the ignition cycle counter will be reset and the diagnostic trouble code will continue to be a stored code.

If a malfunction is not active while performing a diagnostic test procedure,theactivecode diagnostic test will not locatethesourceof the problem. In this case, thestoredcodecan indicate an area toinspect.

Maintain a safe distance from all airbags while performing the following inspection. If no obvious problems are found, erase stored codes, and with the ignition “on” wiggle the wire harness and connectors, rotate the steering wheel from stop to stop. Recheck for codes periodically as you work through the system. This procedure may uncover a malfunction that is difficult to locate.

3.2 AUDIO SYSTEM

The factory installed radio receiver communicates on the Programmable Communication Interface (PCI) data bus network. The PCI Bus inputs into the radio are used for VF dimming and remote steering wheelcontrols.All theradiosare capable of displaying faults and allowing certain actuation tests through the use of the DRBIIIt. When attempting to perform PCI Bus diagnostics, the first step is to identify the radio in use in the vehicle.

GENERAL INFORMATION

When trouble shooting output shorts or “output”

error messages, the following applies:

On radios without anexternalamplifier, theterm output refers to the path between the radio and the speaker. This type of circuit can be monitored all the way through the speaker connections by the radio assembly. When the radio displays a shorted output DTC with this type of system, the speaker, radio, or wiring could be at fault.

On radios with an external amplifier, the term “output” refers to the circuit between the radio connector and the amplifier. The radio is capable of monitoring only this portion and can tell nothing about the circuit between the amplifier and the speakers. Consequently, a shorted output DTC on this type of system would only refer to this circuit. A faulty speaker could not cause this DTC.

3.2.1 REMOTE RADIO CONTROLS

These radios can be controlled via remote radio switches (optional). These switches are located on the back side of the steering wheel. They control mode, preset, seek up, seek down, volume up and volume down functions.

These functions are inputs to the Instrument Cluster (MIC) and can be read with the DRBIIIt. The switches are a multiplexed signal to the MIC. The radio control MUX circuit is a 5 volt line that is pulled to ground through different value resistors built intotheswitches. This causesavoltage drop to be seen by the MIC and it sends a specific message to the radio on the PCI Bus circuit. The radio then responses to the message.

This circuit is fairly simple to troubleshoot. The circuit must be complete from the switches in the steering wheel to the MIC. The ground must be complete so that the switches can cause the voltage drop for the MIC to see. The circuit passes through the clockspring so continuity through this devise must be verified.

3.2.2 AMPLIFIER (PREMIUM SYSTEM)

The Premium Audio Amplifier uses a microprocessor for audio digital signal processing (DSP) and system diagnostics. DSP provides a more accurate and consistent match of the audio system equalization to the vehicle interior. The DR Ram amplifier has six channels for superior sound quality.

The amplifier reads the VIN from the PCI bus and sets itself to match the vehicle. The amplifier will send four beeps to the vehicle speakers at ignition on, if it does not read the VIN correctly. A replacement amplifier may beep at the first power up, but if these beeps are heard after the first ignition on, the DRBIIIt should be used to verify the amplifier is connected to the PCI bus and that the VIN on the PCI bus is correct.

The amplifier, wiring to the speakers and the speakers work independently from the radio. The amplifier’s microprocessor supports several diagnostic functions. Tests can be run from the DRBIIIt that will help in diagnosing audio system problems. The DRBIIIt can display fault messages when an input or outputproblemto the amplifier is detected. The amplifier can detect wiring shorts and suggest which wires are likely to be shorted. The amplifier can send test signals that can be used to verify that the amplifier, speakers, and wiring to the speakers are operating properly. The amplifier can also be used to test if the radio is sending audio signals to it. The DRBIIIt can be used to verify the amplifier equalization setting matches the vehicle, in case there is a sound quality complaint. Using the DRBIIIt audio system diagnostics can determine the nature of the problem.

Diagnostic tests the Amplifier can perform through the DRBIIIt: Continuous Tone Test - This test will send a continuous tone to each speaker and will verify the integrity of an individual channel. PCI Amplifier Test - This test will detect a PCI bus or checksum failure. Input Test - This test will detecttheactivityonthe amplifiers input channels from the radio. Speaker Output Test - This test will detect the activity on the amplifiers output channels to the speakers.

3.2.3 NAVIGATION RADIO

The optional navigation radio system receives GPS signals from up to eight satellites to display the position and direction of the vehicle. Map information is supplied through a DVD-ROM. An electronic gyrosensor and the vehicle’s speed sensor enable the system to display the present vehicle position even in locations where GPS signals may be blocked.

When a destination is selected, the navigation system uses information from the map to quickly calculate a route. As the vehicle is driven along the chosen route, the operator is guided with pictorial displays and voice prompts. For complete operating instructions, refer to the manual included with the vehicle.

3.3 COMMUNICATION

The Programmable Communication Interface or PCI Bus is a single wire multiplexed network capable of supporting binary encoded messages shared between multiple modules. The PCI bus circuit is identified as D25. Additional tracer colors may be added to the violet in order to distinguish between

GENERAL INFORMATION

different module connections. The modules are wired in parallel. Connections are made in the harness using splices.

The following modules are used on this vehicle:

• Front Control Module

• Airbag Control Module

• Controller Antilock Brake

• A/C Heater Control Module

• Powertrain Control Module (gas only)

• Engine Control Module (diesel only)

• Radio

• Amplifier (if equipped)

• Hands Free Module

• Transfer Case Control Module (if equipped)

• Sentry Key Immobilizer Module

• Compass Mini-Trip Computer (if equipped)

• Electro/Mechanical Instrument Cluster

Each module provides its own bias and termination in order to transmit and receive messages. The bus voltage is at zero volts when no modules are transmitting and is pulled up to about seven and a half volts when modules are transmitting.

The bus messages are transmitted at a rate averaging 10800 bits per second. Since there is only voltage present when the modules transmit and the message length is only about 500 milliseconds, it is ineffective to try and measure the bus activity with a conventional voltmeter. The preferred method is to use the DRBIIIt lab scope. The 12v square wave selection onthe20-volt scale provides a goodviewof the bus activity. Voltage on the bus should pulse between zero and about seven and a half volts. Refer to the following figure for some typical displays.

The PCI Bus failure modes are broken down into two categories. Complete PCI Bus Communication Failure and individual module no response. Causes of a complete PCI Bus Communication Failure include a short to ground or battery on the PCI circuit. Individual module no response can be caused by an open PCI circuit at the module, or an open battery or ground circuit to the affected module.

Symptoms of acompletePCI Bus Communication Failure would include but are not limited to:

• All gauges on the EMIC stay at zero

• All telltales on EMIC illuminate

• EMIC backlighting at full intensity

• Dashed lines in the overhead console ambient

temperature display

• No responsereceivedfrom any module onthe PCI

bus (except the ECM/PCM)

• No start (if equipped with Sentry Key Immobi-

lizer)

Symptoms of Individual module failure could include any one ormoreofthe above. The difference would be that at least one or more modules would respond to the DRBIIIt.

Diagnosis starts withsymptomidentification. If a complete PCI Bus Communication Failure is suspected, begin by identifying which modules the vehicle is equipped with and then attempt to get a response fromthemodules with the DRBIIIt.Ifany modules are responding, thefailureisnotrelated to the total bus, but can be caused by one or more modules PCI circuit or power supply and ground circuits. The DRBIIIt may display “BUS 6 SIGNAL OPEN” or “NO RESPONSE” to indicate a communication problem. These same messages will be displayed if the vehicle is not equipped with that particular module. The CCD error message is a default message usedbytheDRBIIIt and in no way indicates whether or not the PCI bus is operational. The message is only an indication that a module is either not respondingorthevehicle is not equipped.

GENERAL INFORMATION

NOTE: The 2004 DR 3.7L, 4.7L, and 5.7L vehicles are equipped with the Powertrain Control Module and Transmission Control Module combined in a single control module. This module is the Next Generation Controller (NGC) for DaimlerChrysler and will be referred to as the Powertrain Control Module (PCM). The PCM has four color coded connectors C1/A through C4/D, (C1/A - BLK, C2/B - ORANGE, C3/C - WHITE, C4/D GREEN), with each connector containing 38 pins. The 5.9L Electronic Fuel Injection 24 valve Turbo Diesel has an Engine control module (ECM) CM845. New Diagnostic procedures and New DTC numbers are two of the changes you will see which reflect the new combined module technology. There are new Verification tests and module replacement procedures for the new PCM.

Two tools are required to diagnose and repair the PCM terminals and harness connectors:

1. Miller #3638 Terminal Removal Pick must be used to release the connector terminals or harness and connector damage will occur.

2. Miller #8815 Pinout Box must be used to probe the PCM terminals or terminal damage will occur.

3.4 COMPASS MINI-TRIP COMPUTER (CMTC)

When equipped, the Compass/Mini Trip Computer (CMTC) is located in the overhead console. The CMTC supplements the standard vehicle instrumentation. The CMTC uses a vacuum fluorescent (VF) display to supply the vehicle operator with a compass heading, outdoor temperature, average fuel economy, distance to empty, trip odometer, and elapsed ignition on time. If equipped, the CMTC is also available with an integrated Universal Garage Door Opener (UGDO) known as HomeLinkt.

The CMTC function buttons are labeled C/T, RESET, STEP,andUS/M.The three UGDO buttons are labeled with dots to indicate the channel number.

Most of theCMTCdisplay information is received over the PCI bus. The CMTC sends and receives data over the PCI bus, communicating with the FCM (Diesel), PCM (3.7L, 4.7L, 5.7L), and the Instrument Cluster.

GENERAL INFORMATION

3.4.1 VEHICLE INFORMATION DISPLAY

The CMTC provides the following functions:

• Compass direction

• Outside temperature

• Elapsed ignition on time

• Distance to empty

• Average fuel economy

• Trip Odometer

The CMTC will not display information for any of the screens for which it did not receive the proper PCI bus data. Refer to the symptom list in the Overhead Console section for problems related to the CMTC.

The CMTC receives the following messages from the Instrument Cluster:

• Verification of US/Metric status

• VF display dimming brightness and exterior

lamp status

• Trip Odometer data

The CMTC receives the following message from the PCM:

• Vehicle Speed

US/M BUTTON

The US/M button is used to toggle the display between English and Metric measurement units.

STEP BUTTON

The STEP Button can be used in one of the following ways:

1. To sequentially select one of 4 displays or blank

display in the following order:

• Average Fuel Economy

• Distance to Empty

• Trip Odometer

• Time Elapsed

• Off (Blank)

2. To set the magnetic variance zone when VARI-

ANCE=X(X=1-15)isindicated in the VF display.

RESET BUTTON

The RESET Button has two different functions:

1. To clear the trip functions that may be reset

2. To enter and exit the diagnostic mode

Pressing the RESET button once will clear the trip function that is currently being displayed and the CMTC will send a PCI bus beep request to the Instrument Cluster. If the RESET button ispressed again within 3 seconds, the CMTC will reset ALL of the trip functions and an additional beep request is sent to the Instrument Cluster. The trip functions that may be reset are:

• Average Fuel Economy

• Trip Odometer

• Elapsed Time

A reset will only occur if one of the trip functions

that may be reset is currently being displayed.

The CMTCmodulewillsend a beep request tothe

Instrument Cluster.

Simultaneously pressing the RESET button and the C/T button while turning the ignition from Off to On will enter the CMTC into the self-diagnostic mode.

COMPASS/TEMPERATURE (C/T) BUTTON

Actuating the Compass/Temperature Button (C/T) will cause the CMTC to display the compass and temperature information. This function will operate from another traveler display. The CMTC simultaneously displays the compass reading and the outside temperature. Outside temperature information is received via the PCI bus from the FCM.

The CMTC module internally senses and calculates the compass direction.

TRAVELER DISPLAY FUNCTIONS

Using the STEP button will change the CMTC between modes of operation and display the appropriate information according to data received from the PCI Bus.

COMPASS OPERATION

Upon ignition on, if the calibration information stored in the CMTC memory is within the normal range, the CMTC will perform in slow Auto-Cal mode. In slow Auto-Cal mode, the CMTC continuously compensates for the slowly changing magnetic field of the vehicle. The compass module detects changes in the vehicle magnetism and makes appropriate internal corrections to ensure proper displayed direction.

However, if the calibration information stored in the CMTC memory is not within the normal range at ignition on, the CMTC will enter fast Auto-Cal. CAL is displayed along with the temperature.

Auto activation of the fast Auto-Cal mode will also occur when the CMTC is subjected to high magnetic field strength levels, which cause all compass readings to be erroneous for a continuous period of five (5) minutes. During fast Auto-Cal, CAL will be displayed along with the temperature.

FastAuto-Cal can also be performed manually, by pressing and holding the RESET button for 10 seconds during the Compass/Temperature display mode.

SETTING MAGNETIC ZONE VARIANCE

Variance is the difference between magnetic North and geographic North. For proper compass function, the correct variance zone must be set. Refer to the Zone Variance map for the correctzone. Follow these steps to check or change the variance zone:

GENERAL INFORMATION

• The ignition switch must be in the On position

and the CMTC display must not be blank.

• If the compass/temperature data is not currently

being displayed, momentarily press and release the C/T button to display compass/temp information.

• Press and hold the RESET button until VARI-

ANCE = XX is displayed. The CMTC will display the variance zone stored in memory and the word VARIANCE.

• Use the STEP button to select the proper vari-

ance zone number, 1 through 15.

• After selecting the proper zone number, momen-

tarily press and release the RESET button. The variance zone is then stored in the memory and the CMTC returns to normal operation.

COMPASS CALIBRATION

The compass module has 2 types of autocalibration; slow-cal and fast-cal. Slow-cal ensures that during normal vehicle operation the compass performs auto-calibration functions to keep the compass sensors in their proper operating range. Whenever theignitionis On andtheCMTC receives PCI bus data indicating that engine RPM is greater than zero, auto-calibration is performed continuously.

If the calibration information stored in the compass module memory is not within the normal range after a power-up cycle, the compass will display CAL. The CMTC will enter into the fast-cal mode until calibration is complete.

To enter the compass into Manual Calibration mode, perform the following steps:

• Drive the vehicle to an area away from any large

metal objects or overhead power lines.

• Ensure that the proper variance zone is selected.

See 9Setting Magnetic Zone Variance.9

• The ignition switch must be in the On position

and the CMTC display must not be blank.

• Press the C/T button to view the Compass/

Temperature display.

• Press and hold the RESET button until CAL is

displayed, then release the button.

• Drive slowly, less than 5 MPH (8KPH) in at least

1 complete 360-degree circle.

• CAL will remain illuminated to alert the driver

that the compass is in the calibration mode.

• After calibration is complete, CAL will turn off.

If the compass appears blank, unable to be calibrated, or the compass displays false indications, the vehicle must be demagnetized. Refer to Compass Demagnetizing Procedure in the Service Manual.

SELF-CHECK DIAGNOSTICS

The CMTC is capable of performing a diagnostic self check on its internal functions. CMTC diagnostics may be performed using a DRBIIIt or by using the following procedure:

1. With the ignition switch in the OFF position,

depress and hold the RESET and the C/T buttons.

2. Turn the ignition switch to the ON position.

3. Continue to hold both buttons until the software

versions are displayed, then release the buttons.

4. All of the VFD segments will illuminate for 2-4

seconds. Check for segments that do not illuminate or illuminate all the time.

5. When the self-check is complete the CMTC will

display one of the following messages:

• PASS

• FAIL

• NO BUS

6. To exit the self-check mode, depress the RESET

button or cycle the ignition switch and the CMTC will return to normal operation.

If aCommunicationfault is displayed,referto the symptom list. If a FAILED SELF TEST is displayed, the CMTC must be replaced.

AMBIENT TEMPERATURE SENSOR

The ambient air temperature is monitored by the FCM or the PCM and displayed by the CMTC. For Diesel equipped vehicles, the FCM receives a hardwire input from the ambient temperature sensor (ATS). For 3.7L, 4.7L and 5.7L equipped vehicles, the PCM receives the hardwire input from theATS.

The ATS is a variable resistor that operates on a 5-volt reference signal circuit hardwired from the FCM or PCM. The resistance in theATS changes as the outside temperature rises or falls. The FCM or PCM senses the change in reference voltage through theATS resistor. Based on the resistance of the ATS, the FCM or PCM is programmed to correspond to a specific temperature. The FCM or PCM stores and filters the ambient temperature data and transmits this data to the CMTC via the PCI Bus. TheATS cannot be adjusted or repaired and, if faulty or damaged, it must be replaced.

GENERAL INFORMATION

AMBIENT TEMPERATURE SENSOR FAULT CODES

The outside temperature function is supportedby the ambienttemperaturesensor(ATS), asignaland ground circuit hardwired to the FCM or the PCM, and the CMTC display.

If theCMTCdisplay indicates 54°C (130°F) orthe ATS sense circuit is open, the temp display will be 54°C (130°F) to indicate an OPEN circuit condition.

If the CMTC display indicates -40°C (-40°F) or theATS sense circuit is shorted to ground, the temp display will be -40°C (-40°F) to indicate a SHORT circuit condition.

If there is an OPEN or SHORT circuit condition, it must be repaired before the CMTC VFD can be tested.

The ATS is supported by the FCM or PCM. Ambient Temperature Sensor DTCs will be recorded in the FCM or PCM. The ATS can be diagnosed using the following Sensor Test. Test the ATS circuits using the diagnostics in the Body Diagnostic Procedures Manual. If the CMTC passes the self test, and the ATS, the circuits, and PCI bus communications are confirmed to be OK, but the CMTC temperature display is inoperative or incorrect, replace the FCM or PCM as required.

AMBIENT TEMPERATURE SENSOR TEST

1. Turn the ignition OFF.

2. Disconnect the ATS harness connector.

3. Measure the resistance of the ATS using the

following min/max values:

• 0° C (32° F) Sensor Resistance = 29.33 - 35.99

Kilohms

• 10° C (50° F) Sensor Resistance = 17.99 - 21.81

Kilohms

• 20° C (68° F) Sensor Resistance = 11.37 - 13.61

Kilohms

• 25° C (77° F) Sensor Resistance = 9.12 - 10.86

Kilohms

• 30° C (86° F) Sensor Resistance = 7.37 - 8.75

Kilohms

• 40° C (104° F) Sensor Resistance = 4.90 - 5.75

Kilohms

The sensor resistance should read between these min/max values. If the resistance values are not OK, replace the Sensor.

HOMELINKt UNIVERSAL TRANSMITTER

If equipped, the HomeLinkt Universal Transmitter is integrated into the overhead console. For added security it will operate home security systems that use coded signals known generically as Rolling Codes. The overhead console display provides visual feedbacktothe driver,indicatingwhich HomeLinkt transmitter channel button is being pressed. The HomeLinkt can learn and store up to

three separate transmitter radio frequency codes to operate garage door openers, security gates, and security lighting. The HomeLinkt buttons are marked with one, two, or three dots. For complete information, refer to Universal Transmitter in the Service Manual or the Owner’s Manual.

3.5 DOOR AJAR SYSTEM

The door ajar state is usedasaninputfor various control modules on the vehicle. The DRBIIIt will display the state ofthedoorajar switches in Inputs/ Outputs. It’s important to note, that when a door is closed, the switch state on the DRBIIIt will show OPEN, and when the door is open, the switch state will show CLOSED. During diagnosis, if a door is closed and the DRBIIIt displays the switch state as CLOSED, it indicates a shorted door ajar circuit. If the door is open and the DRBIIIt displays the switch stateasOPEN, it indicates anopendoor ajar circuit.

3.6 ELECTRICALLY HEATED SYSTEMS

HEATED MIRROR RELAY

A button located on the HVAC control head controls the Heated Mirror Relay, which is located in the IPM. The HVAC control will ground the Heated Mirror Relay Control circuit to energize this relay. The relay control circuit is continuously monitored for certain malfunctions that the HVAC will report as DTCs.

3.7 EXTERIOR LIGHTING SYSTEM

The Instrument Cluster monitors the Headlamp Switch and Multifunctions Switch on its MUX line. The InstrumentClustersends a PCIbusmessage to the Front Control Module (FCM) to actuate the Headlamps ON when the ignition switch is ON and when an open or short failure occurs on the headlamps switch input circuit to the instrument cluster. If the exterior lamps are left ON and the ignition switch OFF for more than 5 minutes, the FCM will turn the exterior lamps off. This feature prevents the battery from being discharged when the Exterior Lamps have been left ON.

3.8 FRONT CONTROL MODULE

The Front Control Module (FCM) is a microprocessor-based electrical control and interface center located in the engine compartment. When it is mated to the Power Distribution Center (PDC), it is referred to as the Integrated Power Module (IPM). The IPM, with its fuses and relays provides power and signal distribution throughout most of the vehicle. The FCM receives hard-wired

GENERAL INFORMATION

analog and resistor multiplexed inputs as well as digital electronic inputs from other electronic modules in the vehicle electrical system through its connection to the IPM and the Programmable Communications Interface (PCI) data bus network. Based on these inputs and programming, the FCM uses high side drivers to provide direct power feeds and low side drivers to provide relay control for some of the vehicle’s most critical electrical systems.

The FCM provides the following features:

Controlled Feeds:

• Brake lights

• Headlamp power

• Turn signals (front & rear)

• Windshield washer pump motor

Relay Controls

• Adjustable pedals relay (when equipped)

• Fog lamp relay (when equipped)

• Horn relay

• Park lamp relay

• Trailer tow relays

• Wiper on/off relay

• Wiper high/low relay

Electrical Inputs

• Module battery supply

• Power ground

• Ignition switch RUN or START position status

• PCI bus

• Wiper park switch

• Washer fluid level switch

• Ambient Temperature sensor

• Battery (+) connection detection

3.8.1 CONTROLLED POWER FEEDS

Headlamp Power

The headlamp switch is a direct input to the instrument cluster which is sometimes known as the Cab Control Node (CCN). The instrument cluster sends a Programmable Communications Interface (PCI) bus message to the FCM informing it of a headlamp switch status change. The FCM then turns power on or off (depending on the bus message) to the headlamps through four 9fuseless9 circuits. These circuits are electronically controlled and continuously monitored for malfunctions. Power is supplied to each filament in a separate circuit. For vehicles equipped with Daytime Run-

ning Lamps (DRL), the FCM electronically steps down the headlamp voltage to provide the desired illumination levels.

Washer Pump Motor

The washer switch is a direct input to the instrument cluster. The instrument cluster sends a PCI bus message to the FCM informingitofarequest to wash. The washer pump motor is then powered through low side control inside the FCM.

This circuit is electronically controlled and continuously monitored for malfunctions. In addition, the FCM electronically protects the washer pump motor from system voltages higher than 16 volts by automatically switching off the low side circuit.

If the FCM receives a prolonged request to wash lasting 30 seconds or more, it will treat the request as a stuck switch condition and deactivate the washer pump motor. The FCM will not reactivate the washer pump motor until there is at least a two second break in the request to wash from the instrument cluster.

3.8.2 RELAY CONTROLS

Adjustable Pedals Relay

If equipped, theadjustablepedalsrelay,whennot activated, supplies fused battery power to the adjustable pedals switch. If the FCM receives a bus message that the vehicle is in reverse or that the cruise control is engaged, it will apply a ground to the adjustable pedals relay control circuit. The ground will activate the relay which will open the power circuit to the adjustable pedals switch. The relay control circuit is continuously monitored for malfunctions which the FCM will report as DTCs.

Fog Lamp Relay

If equipped, the fog lamp switch is a direct input to the instrument cluster. The instrument cluster sends a PCI bus request to the FCM to turn on the fog lamp relay. The fog lamp relay is then actuated by the FCM through low side control. This circuit is electronically controlled and continuously monitored for malfunctions.

Horn Relay

The Horn Relay, which is internal to the IPM, is controlled by the FCM through PCI bus messages from the instrument cluster. These bus messages will be sent when either the horn switch is pressed which is hardwiredtothe instrument cluster,panic mode is requested from the RKE or for vehicle theft security reasons (if equipped). The relay control circuit is continuously monitored for malfunctions that the FCM will report as DTCs.

GENERAL INFORMATION

Park Lamp Relay

The park lamp switch is a direct input to the instrument cluster. The instrument cluster sends a PCI bus request to the FCM to actuate the park lamp relay. The park lamp relay is then actuated through the low side control circuit. This circuit is electronically controlled and continuously monitored for malfunctions.

Wiper High/Low Relay

The wiper switch is a direct input to the instrument cluster. The instrument cluster sends a PCI bus request to the FCM to actuate the wiper high/ low relay.The relay switches powerbetweenthe low speed and high speed of the wiper motor. The wiper high/low relayisthenactuated through the low side control circuit. This circuit is electronically controlled and continuously monitored for malfunctions.

Wiper On/Off Relay

The wiper switch is a direct input to the instrument cluster. The instrument cluster sends a PCI bus request to the FCM to actuate the wiper on/off relay. The wiper on/off relay is then actuated through the low side control circuit. This relay switches power to the wiper high/low relay. This circuit is electronically controlled and continuously monitored for malfunctions.

3.8.3 ELECTRICAL INPUTS

Module Battery Supply

12 Volt input for all FCM functions except headlamp operation.

Power Ground

Ground source for all FCM functions

Ignition Switch RUN or START Position Status

12 volt input to inform the FCM of the ignition switch status for related FCM functions.

PCI Bus

Approximately 7.5 volt input to allow the FCM to communicate with other modules on the PCI bus.

Wiper Park Switch

Ground input used to determine the park placement of the wipers. The ground is also used as feedback to the FCM to determine wiper operating mode.

Washer Fluid Level Switch

Ground input from the washer fluid level switch which closes when washer fluid is low.

Battery (+) Connection Detection

12 volt supply used to monitor battery connection to the IPM. The battery connection to the IPM uses an internal switch to check integrity of the connection and that the Connector Positive Assurance (CPA) is engaged. If the CPA is not properly engaged, a voltage is sent to the FCM to be interpreted as an unseated connector which will set a Diagnostic Trouble Code (DTC).

3.9 HEATING & A/C SYSTEM

3.9.1 SYSTEM AVAILABILITY

• Depending on the model, either a Single-Zone or

Dual-Zone HVAC system is available in these

vehicles.

3.9.2 SYSTEM CONTROLS

The Heater Control Module:

• is fully addressable with the DRBIIIt.

• communicates over the Programmable Commu-

nication Interface Multiplex System (PCI) Bus.

• controls blower motor operation, providing four

blower speeds (Low, M1, M2, & High).

• controls heated mirror and EBL operation (if

equipped).

• controls electric door actuator operation.

The A/C-Heater Control Module:

• is fully addressable with the DRBIIIt.

• communicates over the Programmable Commu-

nication Interface Multiplex System (PCI) Bus.

• uses input from the evaporator temperature sen-

sor to prevent evaporator freeze up while main-

taining optimum cooling performance.

• provides an A/C request to the Powertrain Con-

trol Module (PCM) over the PCI Bus when com-

pressor operation is desired.

• controls blower motor operation, providing four

blower speeds (Low, M1, M2, & High).

• controls heated mirror and EBL operation (if

equipped).

• controls electric door actuator operation.

• A simplifiedcontrolsystem for operation of the

mode, recirculation, and temperature control actuators provides positive positioning without the complexity of feedback from position sensors. The A/C - Heater Control Module knows the number of operating actuator revolutions required for full door travel as well as the number ofactuatorcommutatorpulses per revolution. Using these parameters, the A/C Heater Control Module runs the actuator for the number of commutator pulses that corre-

GENERAL INFORMATION

spond tothedesired door position.To maintain accuracy, the system recalibrates itself periodically at known zero and full travel conditions.

The Single-Zone HVAC system uses:

• one, two-wire electric blend door actuator.

• two, two-wire electric mode door actuators.

• one, two-wire electric recirculation door actuator.

The Dual-Zone HVAC system uses:

• two, two-wire electric blend door actuators.

• two, two-wire electric mode door actuators.

• one, two-wire electric recirculation door actuator.

3.9.3 SYSTEM REVISIONS

The 2004 DR, HVAC system remains carryover from 2003.

3.9.4 SYSTEM DIAGNOSTICS

Fault detection is through active and stored Diagnostic Trouble Codes (DTCs)

• DTCs are displayed by the DRBIIIt.

• Active DTCs are those which currently exist in

the system. The condition causing the fault must be repaired in order to clear this type of DTC.

• Stored DTCs are those which occurred in the

system since the A/C-Heater Control Module received the last 9clear diagnostic info9 message.

The A/C Cooldown Test:

• is actuated with the DRBIIIt.

• checks A/C system performance based on evapo-

rator temperature sensor input.

• will not run if ambient temperature is below

12.7°C (55°F).

• will pass if the evaporator temperature drops

6.7°C (20°F) within two minutes of starting the test.

• faults display on the DRBIIIt as test messages

only after running the test.

• faults will not display on the DRBIIIt as Diag-

nostic Trouble Codes.

• will causetheA/C modeswitchstatus indicator to

flash while the test is running.

• If the test fails, the status indicator will con-

tinue to flash until either the test returns passed or the ignition key is cycled. It will also prevent the EBL mode switch status indicator from indicating EBL operating status. However, the EBL mode switch will continue to function in this state.

The HVAC Door Recalibration function:

• is actuated with the DRBIIIt.

• monitors for door span faults.

• faults display on the DRBIIIt as test messages

only after running the test.

• faults will not display on the DRBIIIt as Diag-

nostic Trouble Codes.

• will cause the EBL mode switch status indicator

to flash while the test is running.

• If the test fails, the status indicator will con-

tinue to flash until either the test returns passed or the ignition key is cycled. It will also prevent the A/C mode switch status indicator from indicating A/C operating status. However, the A/C mode switch will continue to function in this state.

The Actuator Circuit Test:

• is actuated with the DRBIIIt.

• monitors for shorted actuator circuits.

• allows servicetoeasily diagnose and troubleshoot

up to three simultaneous shorts.

• supplements the continuous diagnostics on the

actuator drive system.

• faults display on the DRBIIIt as test messages

only after running the test.

• faults will not display on the DRBIIIt as Diag-

nostic Trouble Codes.

When Performing The Actuator Circuit Test

CAUTION: To ensure a proper diagnosis, repair all Short Too Complex messages first, all common door driver circuit related messages second, and all other door driver circuit related messages last.

CAUTION: The DRBIIIT can display up to three Actuator Circuit Test messages at a time. After repairing each Actuator Circuit Test message, cycle the ignition switch, then rerun the Actuator Circuit Test to ensure no new messages exist.

• The Short Too Complex message:

• indicates that a specific determination of

which lines are shorted could not be made.

• is caused by more than three drivers being

shorted in the same direction. For example, four drivers all shorted to ground, or two or more drivers shorted with at least one driver shorted to ignition/battery and one driver shorted to ground.

• Messages displaying:

• XXX Driver/Circuit Shorted to Ignition/

Battery will set on a per-driver basis.

• XXX Driver/Circuit Shorted to Ground will set

on a per-driver basis.

• the same two drivers/circuits shorted to

GENERAL INFORMATION

ignition/battery as-well-as shorted to ground indicates that two actuator driver circuits are shorted together.

• When the test returns passed, then troubleshoot-

ing should proceed to clearing faults and running the HVAC Door Recalibration system test as a final check of system health.

3.10 INSTRUMENT CLUSTER

The DR Instrument Cluster is a new type of control module that includes the hardware and software necessary to function as the cluster and the body control module. The Instrument Cluster houses the Speedometer, Tachometer, Fuel gauge, Coolant Temperature gauge, Oil Pressure gauge, and the Voltage gauge. The cluster positions all of the gauges using PCI bus messages received from the PCM. The cluster contains certain warning indicators, depending on engine type and options. Some of the indicators are hardwire inputs and some indicators are controlled via PCI bus messages. The warning chime tone generator is contained within the cluster. The cluster includes a vacuum fluorescent (VF) display for the PRNDL, Total and Trip Odometers. The VF will also display warning messages such as door ajar, low washer fluid level, engine hours, and no bus communications. The cluster has the ability to set and store DTCs, communicate on the PCI bus, display engine information, and display certain inputs using the DRBIIIt.

The following systems are controlled either completely by the Instrument Cluster or in conjunction with other inputs received by hardwire or via the PCI bus:

• Audible Warnings

• Brake Lamp Control

• Brake Transmission Shift Interlock (BTSI)

• Cargo Lamp Control

• Central Locking

• Door Lock Inhibit

• Enhanced Accident Response

• Exterior Lighting Control

• Exterior Lighting Fail-Safe

• Heated Seat Control

• Horn Control

• Interior Lamp Control

• Interior Lamps - Enhanced Accident Response

• Interior Lamps Load Shedding

• Lamp Out Indicator Control

• Panel Lamps Dimming Control

• Parade Mode

• Power Locks

• Remote Keyless Entry (RKE)

• Remote Radio Switch Interface

• Rolling Door Locks

• Turn Signal and Hazard Warning Lamp Control

• Vacuum Fluorescent Display Synchronization

• Vehicle Theft Security System (VTSS)

CAUTION: Instrument clusters used in this model automatically configure themselves for compatibility with the features and optional equipment in the vehicle in which they are initially installed. The instrument cluster is programmed to do this by embedding the Vehicle Identification Number (VIN) and other information critical to proper cluster operation in electronic memory. This embedded information is learned through electronic messages received from other electronic modules in the vehicle over the Programmable Communications Interface (PCI) data bus, and through certain hard wired inputs received when the cluster is connected to the vehicle electrically.

Once configured, the instrument cluster memory may be irreparably damaged and certain irreversible configuration errors may occur if the cluster is connected electrically to another vehicle; or, if an electronic module from another vehicle is connected that provides data to the instrument cluster (including odometer values) that conflicts with that which was previously learned and stored.

Therefore, the practice of exchanging (swapping) instrument clusters and other electronic modules in this vehicle with those removed from another vehicle must always be avoided. Failure to observe this caution may result in instrument cluster damage, which is not reimbursable under the terms of* the product warranty. Service replacement instrument clusters are provided with the correct VIN, and the certified odometer and engine hours values embedded in cluster memory, but will otherwise be automatically configured for compatibility with the features and optional equipment in the vehicle in which they are initially installed.

GENERAL INFORMATION

For complete Description and Operation of the Instrument Cluster, refer to the DRServiceManual Instrument Cluster Section. For information regarding systems such as Wiper/Washer, RKE, Lighting, etc., refer to those section titles in this publication and the DR Service Manual.

3.10.1 DIAGNOSTIC SELF TEST

The Instrument Cluster is capable of performing a Diagnostic Self Test. This self test can be initiated manually by depressing and holding the trip reset button while cycling the ignition from the Off to the On position. The self test can also be activated using the DRBIIIt. During the self test, all of the PCI bus indicators will be illuminated. The speedometer, tachometer, fuel gauge, oil pressure gauge, coolant temperature gauge, and voltage gauge will position at their calibration points. The VF display will illuminate all segments and also display the software version. The chime will sound. When the self test is complete, the cluster will return to normal operation. Turning the ignition to the Off position or the cluster detecting engine RPM greater than 0 (zero) will stop the self test.

3.11 INTERIOR LIGHTING

The Instrument Cluster controls the Interior/ Courtesy Lamps. The Instrument Cluster activates the courtesy lamps when either a Dome Lamp switch is turned on or a door is opened. The Instrument Cluster also monitors the output of the Glove Box and Map lamps. The Cargo lamps are controlled by the Instrument Cluster, it receives an output message from the Headlamp switch to turn on the lamps. The Instrument Cluster provides battery protection by shutting down the interior lamps when a door or courtesy/map lamp is left on or open.

3.12 POWER DOOR LOCKS/REMOTE

KEYLESS ENTRY

The Instrument Cluster in response to the door lock switches or the RKE module directly controls the powerdoorlock motors. TheInstrumentCluster monitors the activation of the door lock motors and will set diagnostic trouble codes when there is an open or short condition. When there is a lock or unlock input from a switch or RKE command, the Instrument Cluster will activate the appropriate driver for 300 milliseconds. If a lock or unlock switch remains active, the request will be ignored until the switch transitions back to off. The lock switches are resistive multiplexed input devices hardwired to the Instrument Cluster.

3.12.1 AUTOMATIC DOOR LOCKS

The Instrument Cluster will automatically lock all the doors when the vehicle speed exceeds 15 MPH (24 KMH), throttle position exceeds 10 percent and all the doors are closed. If a door is opened theAutomatic Door Lock feature shall reset andthe Instrument Cluster will lock the doors when the above conditions are met. This feature is programmable by the customer or the DRBIIIt.

3.12.2 CENTRAL LOCKING/UNLOCKING

The Instrument Cluster will lock all doors when the cylinder lock switch is activated in the 9lock9 position. When the Instrument Cluster receives an unlock command from the driver cylinder lock switch, it will unlock only that door. If the Instrument Cluster receives a second command within a 5-second period it will unlock all the remaining doors. The illuminated entry will activate during door unlock.

3.12.3 DOOR LOCK INHIBIT

When the key is in the ignition, in any position, and either front door is open, the door lock switches LOCK functions are disabled. The UNLOCK functions are still functional. This protects against locking the vehicle with the keys still in the ignition. The RKE transmitter will still lock the doors as usual.

3.12.4 ENHANCED ACCIDENT RESPONSE

Upon detectionofan airbag deployment by wayof the PCI bus, the Instrument Cluster shall:

• Immediately disable the power door lock output

• Unlock all doors by activating the door unlock

output for approximately 300 milliseconds.

• After actuating the door unlock output, allow the

door lock motors to be activated if the door lock input has been inactive (not erratic) for 2 seconds since the reception of the airbag deployment message.

3.13 REMOTE KEYLESS ENTRY

The remotekeylessentry (RKE) feature is usedto control the power door locks and panic feature by using a remote transmitter (keyfob) and receiver located within the instrument cluster. The instrument cluster RKE feature controls the driver door unlock, all doors lock/unlock, horn chirp enabled/ disable, optical chirp enabled/disable, illuminated entry, the panic feature, initiate customer programming, and arming/disarming the Vehicle Theft Security System.

When a valid lock message is received from the receiver, the instrument cluster will:

+ 612 hidden pages

Dodge Ram 2004 Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual