Nissan Xterra Automatic Transmission AT 2000 Owner's Manual

AUTOMATIC TRANSMISSION

CONTENTS

TROUBLE DIAGNOSIS - INDEX ....................................4

Alphabetical & P No. Index for DTC ...........................4

PRECAUTIONS ...............................................................6

Supplemental Restraint System (SRS) ″AIR

BAG″ and ″SEAT BELT PRE-TENSIONER″...............6

Precautions for On Board Diagnostic (OBD)

System of A/T and Engine...........................................6

Precautions..................................................................6

Service Notice or Precautions.....................................8

Wiring Diagrams and Trouble Diagnosis.....................9

PREPARATION .............................................................10

Special Service Tools................................................10

OVERALL SYSTEM ......................................................12

A/T Electrical Parts Location .....................................12

Circuit Diagram..........................................................13

Cross-sectional View .................................................14

Hydraulic Control Circuit............................................15

Shift Mechanism ........................................................16

Control System ..........................................................25

Control Mechanism....................................................26

Control Valve .............................................................31

ON BOARD DIAGNOSTIC SYSTEM

DESCRIPTION...............................................................33

Introduction................................................................33

OBD-II Function for A/T System................................33

One or Two Trip Detection Logic of OBD-II..............33

OBD-II Diagnostic Trouble Code (DTC)....................33

Malfunction Indicator Lamp (MIL)..............................37

CONSULT-II...............................................................37

Diagnostic Procedure Without CONSULT-II..............46

TROUBLE DIAGNOSIS - INTRODUCTION..................53

Introduction................................................................53

Work Flow..................................................................57

TROUBLE DIAGNOSIS - BASIC INSPECTION...........59

A/T Fluid Check.........................................................59

Stall Test....................................................................59

Line Pressure Test.....................................................62

Road Test...................................................................63

SECTION

TROUBLE DIAGNOSIS - GENERAL

DESCRIPTION...............................................................81

Symptom Chart..........................................................81

TCM Terminals and Reference Value........................92

TROUBLE DIAGNOSIS FOR POWER SUPPLY..........96

Wiring Diagram - AT - MAIN......................................96

DTC P0705 PARK/NEUTRAL POSITION (PNP)

SWITCH .........................................................................99

Description.................................................................99

Wiring Diagram - AT - PNP/SW...............................101

Diagnostic Procedure ..............................................102

Component Inspection.............................................104

DTC P0710 A/T FLUID TEMPERATURE SENSOR

CIRCUIT.......................................................................105

Description...............................................................105

Wiring Diagram - AT - FTS......................................107

Diagnostic Procedure ..............................................108

Component Inspection.............................................110

DTC P0720 VEHICLE SPEED SENSOR.A/T

(REVOLUTION SENSOR) ...........................................111

Description............................................................... 111

Wiring Diagram - AT - VSSA/T................................113

Diagnostic Procedure ..............................................114

Component Inspection.............................................115

DTC P0725 ENGINE SPEED SIGNAL .......................116

Description...............................................................116

Wiring Diagram - AT - ENGSS................................117

Diagnostic Procedure ..............................................118

DTC P0731 IMPROPER SHIFTING TO 1ST GEAR

POSITION ....................................................................120

Description...............................................................120

Wiring Diagram - AT - 1ST......................................123

Diagnostic Procedure ..............................................124

Component Inspection.............................................125

DTC P0732 IMPROPER SHIFTING TO 2ND GEAR

POSITION ....................................................................126

Description...............................................................126

Wiring Diagram - AT - 2ND......................................129

Diagnostic Procedure ..............................................130

IDX

CONTENTS (Cont’d)

Component Inspection.............................................130

DTC P0733 IMPROPER SHIFTING TO 3RD GEAR

POSITION ....................................................................132

Description...............................................................132

Wiring Diagram - AT - 3RD......................................135

Diagnostic Procedure ..............................................136

Component Inspection.............................................136

DTC P0734 IMPROPER SHIFTING TO 4TH GEAR

POSITION ....................................................................138

Description...............................................................138

Wiring Diagram - AT - 4TH......................................142

Diagnostic Procedure ..............................................143

Component Inspection.............................................146

DTC P0740 TORQUE CONVERTER CLUTCH

SOLENOID VALVE......................................................147

Description...............................................................147

Wiring Diagram - AT - TCV......................................149

Diagnostic Procedure ..............................................150

Component Inspection.............................................151

DTC P0744 IMPROPER LOCK-UP OPERATION......152

Description...............................................................152

Wiring Diagram - AT - TCCSIG...............................155

Diagnostic Procedure ..............................................156

Component Inspection.............................................159

DTC P0745 LINE PRESSURE SOLENOID VALVE...160

Description...............................................................160

Wiring Diagram - AT - LPSV....................................162

Diagnostic Procedure ..............................................163

Component Inspection.............................................164

DTC P0750 SHIFT SOLENOID VALVE A ..................165

Description...............................................................165

Wiring Diagram - AT - SSV/A..................................167

Diagnostic Procedure ..............................................168

Component Inspection.............................................169

DTC P0755 SHIFT SOLENOID VALVE B..................170

Description...............................................................170

Wiring Diagram - AT - SSV/B..................................172

Diagnostic Procedure ..............................................173

Component Inspection.............................................174

DTC P1705 THROTTLE POSITION SENSOR ...........175

Description...............................................................175

Wiring Diagram - AT - TPS......................................178

Diagnostic Procedure ..............................................179

Component Inspection.............................................183

DTC P1760 OVERRUN CLUTCH SOLENOID

VALVE..........................................................................184

Description...............................................................184

Wiring Diagram - AT - OVRCSV..............................186

Diagnostic Procedure ..............................................187

Component Inspection.............................................188

DTC BATT/FLUID TEMP SEN (A/T FLUID TEMP

SENSOR CIRCUIT AND TCM POWER SOURCE)....189

Description...............................................................189

Wiring Diagram - AT - BA/FTS................................191

Diagnostic Procedure ..............................................192

Component Inspection.............................................194

VEHICLE SPEED SENSOR.MTR................................195

Description...............................................................195

Wiring Diagram - AT - VSSMTR..............................197

Diagnostic Procedure ..............................................198

DTC CONTROL UNIT (RAM), CONTROL UNIT

(ROM)...........................................................................199

Description...............................................................199

Diagnostic Procedure ..............................................200

DTC CONTROL UNIT (EEPROM) ..............................201

Description...............................................................201

Diagnostic Procedure ..............................................202

TROUBLE DIAGNOSES FOR SYMPTOMS...............203

Wiring Diagram - AT - NONDTC.............................203

1. O/D OFF Indicator Lamp Does Not Come On....206

2. Engine Cannot Be Started In P and N Position..208

3. In ″P″ Position, Vehicle Moves Forward Or

Backward When Pushed.........................................209

4. In N Position, Vehicle Moves ..............................210

5. Large Shock. N -> R Position.............................212

6. Vehicle Does Not Creep Backward In R

Position....................................................................214

7. Vehicle Does Not Creep Forward In D, 2 Or 1

Position....................................................................217

8. Vehicle Cannot Be Started From D

9. A/T Does Not Shift: D Kickdown: D

-> D2..................................................223

10. A/T Does Not Shift: D

11. A/T Does Not Shift: D

-> D2Or Does Not

-> D3.............................226

-> D4.............................229

...................220

12. A/T Does Not Perform Lock-up.........................232

13. A/T Does Not Hold Lock-up Condition..............234

14. Lock-up Is Not Released...................................236

15. Engine Speed Does Not Return To Idle (Light Braking D

16. Vehicle Does Not Start From D

17. A/T Does Not Shift: D

-> D3).....................................................237

.......................239

-> D3, When

Overdrive Control Switch ON -> OFF .....................240

18. A/T Does Not Shift: D

-> 22, When Selector

Lever D -> 2 Position ..............................................241

19. A/T Does Not Shift: 2

-> 11, When Selector

Lever 2 -> 1 Position...............................................242

20. Vehicle Does Not Decelerate By Engine

Brake........................................................................243

21. TCM Self-diagnosis Does Not Activate (PNP, Overdrive Control and Throttle Position Switches

Circuit Checks) ........................................................243

A/T SHIFT LOCK SYSTEM.........................................251

Description...............................................................251

Wiring Diagram - SHIFT -........................................252

AT-2

CONTENTS (Cont’d)

Diagnostic Procedure ..............................................253

Component Check...................................................255

KEY INTERLOCK CABLE ..........................................256

Components.............................................................256

Removal...................................................................256

Installation................................................................257

ON-VEHICLE SERVICE ..............................................258

Control Valve Assembly and Accumulators.............258

Revolution Sensor Replacement.............................259

Rear Oil Seal Replacement.....................................259

Parking Components Inspection..............................259

Park/Neutral Position (PNP) Switch Adjustment .....260

Manual Control Linkage Adjustment........................260

REMOVAL AND INSTALLATION...............................261

Removal...................................................................261

Installation................................................................263

OVERHAUL .................................................................264

Components.............................................................264

Oil Channel..............................................................266

Locations of Needle Bearings, Thrust Washers

and Snap Rings.......................................................267

DISASSEMBLY............................................................268

REPAIR FOR COMPONENT PARTS .........................279

Oil Pump..................................................................279

Control Valve Assembly...........................................283

Control Valve Upper Body.......................................289

Control Valve Lower Body.......................................294

Reverse Clutch ........................................................296

High Clutch ..............................................................300

Forward and Overrun Clutches ...............................302

Low & Reverse Brake..............................................306

Forward Clutch Drum Assembly..............................310

Rear Internal Gear and Forward Clutch Hub..........312

Band Servo Piston Assembly..................................315

Parking Pawl Components......................................319

ASSEMBLY..................................................................321

Assembly (1)............................................................321

Adjustment...............................................................329

Assembly (2)............................................................331

SERVICE DATA AND SPECIFICATIONS (SDS).......338

General Specifications.............................................338

Shift Schedule..........................................................338

Stall Revolution........................................................338

Line Pressure...........................................................338

Return Springs.........................................................339

Accumulator O-ring..................................................340

Clutches and Brakes ...............................................340

Oil Pump and Low One-way Clutch........................342

Total End Play..........................................................342

Reverse Clutch Drum End Play ..............................343

Removal and Installation.........................................343

AT-3

IDX

Alphabetical & P No. Index for DTC

TROUBLE DIAGNOSIS — INDEX

Alphabetical & P No. Index for DTC

ALPHABETICAL INDEX FOR DTC

Items

(CONSULT-II screen terms)

A/T 1ST GR FNCTN 1103 P0731 AT-120 A/T 2ND GR FNCTN 1104 P0732 AT-126 A/T 3RD GR FNCTN 1105 P0733 AT-132 A/T 4TH GR FNCTN 1106 P0734 AT-138 A/T TCC S/V FNCTN 1107 P0744 AT-152 ATF TEMP SEN/CIRC 1208 P0710 AT-105 ENGINE SPEED SIG 1207 P0725 AT-116 L/PRESS SOL/CIRC 1205 P0745 AT-160 O/R CLTCH SOL/CIRC 1203 P1760 AT-184 PNP SW/CIRC 1101 P0705 AT-99 SFT SOL A/CIRC*3 1108 P0750 AT-165 SFT SOL B/CIRC*3 1201 P0755 AT-170

ECM*1

DTC

CONSULT-II

GST*2

Reference page

NGAT0179

NGAT0179S01

TCC SOLENOID/CIRC 1204 P0740 AT-147 TP SEN/CIRC A/T*3 1206 P1705 AT-175 VEH SPD SEN/CIR AT*4 1102 P0720 AT-111

*1: In Diagnostic Test Mode II (Self-diagnostic results), these numbers are controlled by NISSAN. *2: These numbers are prescribed by SAE J2012. *3: When the fail-safe operation occurs, the MIL illuminates. *4: The MIL illuminates when both the “Revolution sensor signal” and the “Vehicle speed sensor signal” meet the fail-safe condition at

the same time.

AT-4

TROUBLE DIAGNOSIS — INDEX

Alphabetical & P No. Index for DTC (Cont’d)

P NO. INDEX FOR DTC

DTC

CONSULT-II

GST*2 P0705 1101 PNP SW/CIRC AT-99 P0710 1208 ATF TEMP SEN/CIRC AT-105 P0720 1102 VEH SPD SEN/CIR AT*4 AT-111 P0725 1207 ENGINE SPEED SIG AT-116 P0731 1103 A/T 1ST GR FNCTN AT-120 P0732 1104 A/T 2ND GR FNCTN AT-126 P0733 1105 A/T 3RD GR FNCTN AT-132 P0734 1106 A/T 4TH GR FNCTN AT-138 P0740 1204 TCC SOLENOID/CIRC AT-147 P0744 1107 A/T TCC S/V FNCTN AT-152 P0745 1205 L/PRESS SOL/CIRC AT-160 P0750 1108 SFT SOL A/CIRC*3 AT-165 P0755 1201 SFT SOL B/CIRC*3 AT-170

ECM*1

Items

(CONSULT-II screen terms)

=NGAT0179S02

Reference page

P1705 1206 TP SEN/CIRC A/T*3 AT-175 P1760 1203 O/R CLTCH SOL/CIRC AT-184

the same time.

AT-5

IDX

PRECAUTIONS

Supplemental Restraint System (SRS) “AIR BAG” and “SEAT BELT PRE-TENSIONER”

The supplemental Restraint System such as “AIR BAG” and “SEAT BELTPRE-TENSIONER” used along with a seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain types of collision. The Supplemental Restraint System consists of driver air bag module (located in the center of the steering wheel), front passenger air bag module (located on the instrument panel on passenger side), seat belt pre-tensioners, a diagnosis sensor unit, a crash zone sensor, warning lamp, wiring harness and spiral cable. Information necessary to service the system safely is included in the RS section of this Service Manual.

WARNING:

I To avoid rendering the SRS inoperative, which could increase the risk of personal injury or death

in the event of a collision which would result in air bag inflation, all maintenance must be performed by an authorized NISSAN dealer.

I Improper maintenance, including incorrect removal and installation of the SRS, can lead to per-

sonal injury caused by unintentional activation of the system. For removal of Spiral Cable and Air Bag Module, refer to

I Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this

Service Manual. Spiral cable and wiring harnesses (except “SEAT BELT PRE-TENSIONER”) covered with yellow insulation either just before the harness connectors or for the complete harness are related to the SRS.

RS-16

NGAT0001

Precautions for On Board Diagnostic (OBD) System of A/T and Engine

The ECM has an on board diagnostic system. It will light up the malfunction indicator lamp (MIL) to warn the driver of a malfunction causing emission deterioration.

CAUTION:

I Be sure to turn the ignition switch OFF and disconnect the negative battery terminal before any

repair or inspection work. The open/short circuit of related switches, sensors, solenoid valves, etc. will cause the MIL to light up.

I Be sure to connect and lock the connectors securely after work. A loose (unlocked) connector will

cause the MIL to light up due to an open circuit. (Be sure the connector is free from water, grease, dirt, bent terminals, etc.)

I Be sure to route and secure the harnesses properly after work. Interference of the harness with a

bracket, etc. may cause the MIL to light up due to a short circuit.

I Be sure to connect rubber tubes properly after work. A misconnected or disconnected rubber tube

may cause the MIL to light up due to a malfunction of the EGR system or fuel injection system, etc.

I Be sure to erase the unnecessary malfunction information (repairs completed) from the TCM and

ECM before returning the vehicle to the customer.

NGAT0002

SEF289H

Precautions

I Before connecting or disconnecting the TCM harness

connector, turn ignition switch OFF and disconnect negative battery terminal. Failure to do so may damage the TCM. Because battery voltage is applied to TCM even if ignition switch is turned off.

NGAT0003

AT-6

PRECAUTIONS

Precautions (Cont’d)

I When connecting or disconnecting pin connectors into or

from TCM, take care not to damage pin terminals (bend or break). Make sure that there are not any bends or breaks on TCM pin terminal, when connecting pin connectors.

AAT470A

MEF040DA

SAT964I

I Before replacing TCM, perform TCM input/output signal

inspection and make sure whether TCM functions properly or not. (See page AT-92.)

I After performing each TROUBLE DIAGNOSIS, perform

“DTC (Diagnostic Trouble Code) CONFIRMATION PROCEDURE”. The DTC should not be displayed in the “DTC CONFIRMATION PROCEDURE” if the repair is completed.

I Before proceeding with disassembly, thoroughly clean the out-

side of the transmission. It is important to prevent the internal parts from becoming contaminated by dirt or other foreign matter.

I Disassembly should be done in a clean work area. I Use lint-free cloth or towels for wiping parts clean. Common

shop rags can leave fibers that could interfere with the operation of the transmission.

I Place disassembled parts in order for easier and proper

assembly.

I All parts should be carefully cleaned with a general purpose,

non-flammable solvent before inspection or reassembly.

I Gaskets, seals and O-rings should be replaced any time the

transmission is disassembled.

I It is very important to perform functional tests whenever they

are indicated.

I The valve body contains precision parts and requires extreme

care when parts are removed and serviced. Place disassembled valve body parts in order for easier and proper assembly. Care will also prevent springs and small parts from becoming scattered or lost.

I Properly installed valves, sleeves, plugs, etc. will slide along

bores in valve body under their own weight.

AT-7

IDX

Precautions (Cont’d)

PRECAUTIONS

I Before assembly, apply a coat of recommended ATF to all

parts. Apply petroleum jelly to protect O-rings and seals, or hold bearings and washers in place during assembly. Do not use grease.

I Extreme care should be taken to avoid damage to O-rings,

seals and gaskets when assembling.

I Replace ATF cooler if excessive foreign material is found in oil

pan or clogging strainer. Refer to “ATF COOLER SERVICE” (Refer to AT-9).

I After overhaul, refill the transmission with new ATF. I When the A/T drain plug is removed, only some of the fluid is

drained. Old A/T fluid will remain in torque converter and ATF cooling system. Always follow the procedures under “Changing A/T Fluid” refer to

MA-37

whenchangingA/Tfluid.

Service Notice or Precautions

FAIL-SAFE

NGAT0004

NGAT0004S01

The TCM has an electronic Fail-Safe (limp home mode). This allows the vehicle to be driven even if a major electrical input/output device circuit is damaged. Under Fail-Safe, the vehicle always runs in third gear, even with a shift lever position of 1, 2 or D. The customer may complain of sluggish or poor acceleration. When the ignition key is turned ON following Fail-Safe operation, O/D OFF indicator lamp blinks for about 8 seconds. (For “TCM SELF-DIAGNOSTIC PROCEDURE (No Tools)”, refer to AT-47.) Fail-Safe may occur without electrical circuit damage if the vehicle is driven under extreme conditions (such as excessive wheel spin followed by sudden braking). To recover normal shift pattern, turn the ignition key OFF for 5 seconds, then ON. The blinking of the O/D OFF indicator lamp for about 8 seconds will appear only once and be cleared. The customer may resume normal driving conditions. Always follow the “WORK FLOW” (Refer to AT-57). The SELF-DIAGNOSIS results will be as follows: The first SELF-DIAGNOSIS will indicate damage to the vehicle speed sensor or the revolution sensor. During the next SELF-DIAGNOSIS, performed after checking the sensor, no damages will be indicated.

TORQUE CONVERTER SERVICE

NGAT0004S04

The torque converter should be replaced under any of the following conditions:

I External leaks in the hub weld area. I Converter hub is scored or damaged. I Converter pilot is broken, damaged or fits poorly into crankshaft. I Steel particles are found after flushing the cooler and cooler lines. I Pump is damaged or steel particles are found in the converter. I Vehicle has TCC shudder and/or no TCC apply. Replace only after all hydraulic and electrical diagnoses

have been made. (Converter clutch material may be glazed.)

I Converter is contaminated with engine coolant containing antifreeze. I Internal failure of stator roller clutch. I Heavy clutch debris due to overheating (blue converter). I Steel particles or clutch lining material found in fluid filter or on magnet when no internal parts in unit are

worn or damaged — indicates that lining material came from converter. The torque converter should not be replaced if: I The fluid has an odor, is discolored, and there is no evidence of metal or clutch facing particles.

AT-8

PRECAUTIONS

Service Notice or Precautions (Cont’d)

I The threads in one or more of the converter bolt holes are damaged. I Transmission failure did not display evidence of damaged or worn internal parts, steel particles or clutch

plate lining material in unit and inside the fluid filter. I Vehiclehas been exposed to high mileage (only). The exception may be where the torque converter clutch

dampener plate lining has seen excess wear by vehicles operated in heavy and/or constant traffic, such

as taxi, delivery or police use.

ATF COOLER SERVICE

Replace ATF cooler if excessive foreign material is found in oil pan or clogging strainer. Replace radiator lower tank (which includes ATF cooler) with a new one and flush cooler line using cleaning solvent and compressed air.

OBD-II SELF-DIAGNOSIS

I A/T self-diagnosis is performed by the TCM in combination with the ECM. The results can be read through

the blinking pattern of the O/D OFF indicator or the malfunction indicator lamp (MIL). Refer to the table on

AT-38 for the indicator used to display each self-diagnostic result. I The self-diagnostic results indicated by the MIL are automatically stored in both the ECM and TCM

memories.

Always perform the procedure “HOW TO ERASE DTC” on AT-35 to complete the repair and avoid

unnecessary blinking of the MIL.

I The following self-diagnostic items can be detected using ECM self-diagnostic results mode* only when

the O/D OFF indicator lamp does not indicate any malfunctions.

− Park/neutral position (PNP) switch

− A/T 1st, 2nd, 3rd, or 4th gear function

− A/T TCC S/V function (lock-up) *: For details of OBD-II, refer to

I Certain systems and components, especially those related to OBD, may use a new style slide-

locking type harness connector. For description and how to disconnect, refer to

“Description”, “HARNESS CONNECTOR”.

EC-627

(“ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION”).

Wiring Diagrams and Trouble Diagnosis

When you read wiring diagrams, refer to the followings:

GI-10

I “HOW TO READ WIRING DIAGRAMS” refer to I “POWER SUPPLY ROUTING” for power distribution circuit refer to

When you perform trouble diagnosis, refer to the followings:

I “HOW TO FOLLOW TEST GROUP IN TROUBLE DIAGNOSIS” refer to I “HOW TO PERFORM EFFICIENT DIAGNOSIS FOR AN ELECTRICAL INCIDENT” refer to

EL-9

GI-34

GI-23

NGAT0004S02

NGAT0004S03

EL-5

NGAT0005

AT-9

IDX

Special Service Tools

PREPARATION

Special Service Tools

The actual shapes of Kent-Moore tools may differ from those of special service tools illustrated here.

Tool number (Kent-Moore No.) Tool name

ST2505S001 (J34301-C) Oil pressure gauge set 1 ST25051001 (—) Oil pressure gauge 2 ST25052000 (—) Hose 3 ST25053000 (—) Joint pipe 4 ST25054000 (—) Adapter 5 ST25055000 (—) Adapter

ST07870000 (J37068) Transmission case stand

Description

Measuring line pressure

NT097

Disassembling and assembling A/T

a: 182 mm (7.17 in) b: 282 mm (11.10 in) c: 230 mm (9.06 in) d: 100 mm (3.94 in)

NGAT0006

KV31102100 (J37065) Torque converter oneway clutch check tool

ST25850000 (J25721-A) Sliding hammer

KV31102400 (J34285 and J34285-87) Clutch spring compressor

NT421

Checking one-way clutch in torque converter

NT098

Removing oil pump assembly

a: 179 mm (7.05 in) b: 70 mm (2.76 in) c: 40 mm (1.57 in) dia. d: M12 x 1.75P

NT422

Removing and installing clutch return springs

a: 320 mm (12.60 in) b: 174 mm (6.85 in)

NT423

AT-10

Tool number (Kent-Moore No.) Tool name

PREPARATION

Special Service Tools (Cont’d)

Description

ST33200000 (J26082) Drift

(J34291) Shim setting gauge set

NT091

NT101

Installing oil pump housing oil seal Installing rear oil seal

a: 60 mm (2.36 in) dia. b: 44.5 mm (1.752 in) dia.

Selecting oil pump cover bearing race and oil pump thrust washer

AT-11

IDX

A/T Electrical Parts Location

OVERALL SYSTEM

A/T Electrical Parts Location

NGAT0007

AT-12

AAT622A

OVERALL SYSTEM

Circuit Diagram

NGAT0008

AT-13

AAT580A

IDX

Cross-sectional View

OVERALL SYSTEM

Cross-sectional View

NGAT0010

AT-14

SAT125BA

OVERALL SYSTEM

Hydraulic Control Circuit

NGAT0011

AT-15

SAT624GA

IDX

Shift Mechanism

OVERALL SYSTEM

Shift Mechanism

NGAT0012

The automatic transmission uses compact, dual planetary gear systems to improve power-transmission efficiency, simplify construction and reduce weight. It also employs an optimum shift control and superwide gear ratios. They improve starting performance and acceleration during medium and high-speed operation. Two one-way clutches are also employed: one is used for the forward clutch and the other for the low clutch. These one-way clutches, combined with four accumulators, reduce shifting shock to a minimum.

CONSTRUCTION

NGAT0012S01

1. Torque converter clutch piston

2. Torque converter

3. Oil pump

4. Input shaft

5. Brake band

6. Reverse clutch

7. High clutch

8. Front pinion gear

9. Front sun gear

10. Front internal gear

11. Front planetary carrier

12. Rear sun gear

13. Rear pinion gear

14. Rear internal gear

15. Rear planetary carrier

16. Forward clutch

SAT509I

17. Forward one-way clutch

18. Overrun clutch

19. Low one-way clutch

20. Low & reverse brake

21. Parking pawl

22. Parking gear

23. Output shaft

AT-16

OVERALL SYSTEM

Shift Mechanism (Cont’d)

FUNCTION OF CLUTCH AND BRAKE

Clutch and brake components Abbr. Function Reverse clutch 6 R/C To transmit input power to front sun gear 9. High clutch 7 H/C To transmit input power to front planetary carrier 11. Forward clutch 16 F/C To connect front planetary carrier 11 with forward one-way

clutch 17. Overrun clutch 18 O/C To connect front planetary carrier 11 with rear internal gear 14. Brake band 5 B/B To lock front sun gear 9. Forward one-way clutch 17 F/O.C When forward clutch 16 is engaged, to stop rear internal gear

14 from rotating in opposite direction against engine revolution. Low one-way clutch 19 L/O.C To stop front planetary carrier 11 from rotating in opposite direc-

tion against engine revolution. Low & reverse brake 20 L & R/B To lock front planetary carrier 11.

CLUTCH AND BAND CHART

For-

ward

one-

way

clutch

Low

one-

way

clutch

Low &

reverse

brake

Lock-up Remarks

Shift position

Reverse

clutch

High

clutch

For-

ward

clutch

Over-

run

clutch

2nd

apply

Band servo

3rd

release

4th

apply

=NGAT0012S02

NGAT0012S03

R q q

1st q *1D B B

2nd q *1A q B

D*4

3rd qq*1A *2C C B *5q 4th q C *3C C qq 1st qq BB

2nd qqq B

1st qq BBq

2nd qqq B

*1: Operates when overdrive control switch is being set in OFF position. *2: Oil pressure is applied to both 2nd “apply” side and 3rd “release” side of band servo piston. However, brake band does not contract

because oil pressure area on the “release” side is greater than that on the “apply” side. *3: Oil pressure is applied to 4th “apply” side in condition *2 above, and brake band contracts. *4: A/T will not shift to 4th when overdrive control switch is set in OFF position. *5: Operates when overdrive control switch is OFF. q : Operates. A: Operates when throttle opening is less than 3/16, activating engine brake. B: Operates during “progressive” acceleration. C: Operates but does not affect power transmission. D: Operates when throttle opening is less than 3/16, but does not affect engine brake.

PARK

POSITION REVERSE

POSITION NEUTRAL

POSITION

Automatic

shift

1 k 2 k 3 k

Automatic

shift

1 k 2

Locks (held

stationary) in

1st speed

1 g 2

AT-17

IDX

Shift Mechanism (Cont’d)

OVERALL SYSTEM

POWER TRANSMISSION P and N Positions

I P position

Similar to the N position, no control members operate. The parking pawl interconnected with the select lever engages with the parking gear to mechanically hold the output shaft so that the power train is locked.

I N position

No control members operate. Power from the input shaft is not transmitted to the output shaft since the clutch does not operate.

=NGAT0012S04

NGAT0012S0401

AT-18

SAT039J

OVERALL SYSTEM

Shift Mechanism (Cont’d)

11Position

Forward clutch Forward one-way clutch Overrun clutch Low and reverse brake

Engine brake Overrun clutch always engages, therefore engine brake can be obtained when decelerat-

As overrun clutch engages, rear internal gear is locked by the operation of low and reverse brake. This is different from that of D

ing.

and 21.

=NGAT0012S0406

SAT100J

AT-19

IDX

Shift Mechanism (Cont’d)

OVERALL SYSTEM

D1and 21Positions

Forward one-way clutch Forward clutch Low one-way clutch

Overrun clutch

engagement conditions (Engine brake)

=NGAT0012S0402

Rear internal gear is locked to rotate counterclockwise because of the functioning of these three clutches. (Start-up at D

: Overdrive control switch in OFF

)

Throttle opening less than 3/16

: Throttle opening less than 3/16

At D

and 21positions, engine brake is not activated due to free turning of low one-way

clutch.

AT-20

SAT096J

OVERALL SYSTEM

Shift Mechanism (Cont’d)

D2,22and 12Positions

Forward clutch Forward one-way clutch Brake band

Overrun clutch

engagement conditions

=NGAT0012S0403

Rear sun gear drives rear planetary carrier and combined front internal gear. Front internal gear now rotates around front sun gear accompanying front planetary carrier. As front planetary carrier transfers the power to rear internal gear through forward clutch and forward one-way clutch, this rotation of rear internal gear increases the speed of rear planetary carrier compared with that of the 1st speed.

: Overdrive control switch in OFF

Throttle opening less than 3/16

: Throttle opening less than 3/16

: Always engaged

AT-21

SAT097J

IDX

Shift Mechanism (Cont’d)

OVERALL SYSTEM

D3Position

High clutch Forward clutch Forward one-way clutch

Overrun clutch

engagement conditions

=NGAT0012S0404

Input power is transmitted to front planetary carrier through high clutch. And front planetary carrier is connected to rear internal gear by operation of forward clutch and forward one-way clutch. This rear internal gear rotation and another input (the rear sun gear) accompany rear planetary carrier to turn at the same speed.

: Overdrive control switch in OFF

Throttle opening less than 3/16

AT-22

SAT098J

OVERALL SYSTEM

Shift Mechanism (Cont’d)

D4(O/D) Position

High clutch Brake band Forward clutch

(Does not affect power transmission) Engine brake At D

=NGAT0012S0405

Input power is transmitted to front carrier through high clutch. This front planetary carrier turns around the sun gear which is fixed by brake band and makes front internal gear (output) turn faster.

position, there is no one-way clutch in the power transmission line and engine

brake can be obtained when decelerating.

SAT099J

AT-23

IDX

Shift Mechanism (Cont’d)

OVERALL SYSTEM

R Position

Reverse clutch Low and reverse brake

Engine brake As there is no one-way clutch in the power transmission line, engine brake can be

Front planetary carrier is stationary because of the operation of low and reverse brake. Input power is transmitted to front sun gear through reverse clutch, which drives front internal gear in the opposite direction.

obtained when decelerating.

=NGAT0012S0407

AT-24

SAT101J

OVERALL SYSTEM

Control System

OUTLINE

=NGAT0013

NGAT0013S01

The automatic transmission senses vehicle operating conditions through various sensors. It always controls the optimum shift position and reduces shifting and lock-up shocks.

SENSORS

PNP switch Throttle position sensor Closed throttle position switch Wide open throttle position switch Engine speed signal A/T fluid temperature sensor Revolution sensor Vehicle speed sensor Overdrive control switch ASCD control unit

CONTROL SYSTEM

Shift control Line pressure control Lock-up control

Overrun clutch control Timing control Fail-safe control Self-diagnosis CONSULT communication line Duet-EU control

TCM

ACTUATORS

Shift solenoid valve A Shift solenoid valve B

Overrun clutch solenoid valve Torque converter clutch solenoid valve Line pressure solenoid valve O/D OFF indicator lamp

NGAT0013S02

AAT471A

AT-25

IDX

Control System (Cont’d)

OVERALL SYSTEM

TCM FUNCTION

The function of the TCM is to:

I Receive input signals sent from various switches and sensors. I Determine required line pressure, shifting point, lock-up operation, and engine brake operation. I Send required output signals to the respective solenoids.

INPUT/OUTPUT SIGNAL OF TCM

Sensors and solenoid valves Function PNP switch Detects select lever position and sends a signal to TCM. Throttle position sensor Detects throttle valve position and sends a signal to TCM. Closed throttle position switch Detects throttle valve’s fully-closed position and sends a signal to TCM.

Detects a throttle valve position of greater than 1/2 of full throttle and sends a signal to TCM.

Used as an auxiliary vehicle speed sensor. Sends a signal when revolution sensor (installed on transmission) malfunctions.

Sends a signal, which prohibits a shift to “D TCM.

” (overdrive) position, to the

Input

Wide open throttle position switch

Engine speed signal From ECM. A/T fluid temperature sensor Detects transmission fluid temperature and sends a signal to TCM. Revolution sensor Detects output shaft rpm and sends a signal to TCM.

Vehicle speed sensor

Overdrive control switch

=NGAT0013S03

NGAT0013S04

Output

ASCD control unit

Shift solenoid valve A/B

Line pressure solenoid valve

Torque converter clutch solenoid valve

Overrun clutch solenoid valve

O/D OFF indicator lamp Shows TCM faults, when A/T control components malfunction.

Sends the cruise signal and “D control unit to TCM.

Selects shifting point suited to driving conditions in relation to a signal sent from TCM.

Regulates (or decreases) line pressure suited to driving conditions in relation to a signal sent from TCM.

Regulates (or decreases) lock-up pressure suited to driving conditions in relation to a signal sent from TCM.

Controls an “engine brake” effect suited to driving conditions in relation to a signal sent from TCM.

” (overdrive) cancellation signal from ASCD

Control Mechanism

LINE PRESSURE CONTROL

TCM has the various line pressure control characteristics to meet the driving conditions. An ON-OFF duty signal is sent to the line pressure solenoid valve based on TCM characteristics. Hydraulic pressure on the clutch and brake is electronically controlled through the line pressure solenoid valve to accommodate engine torque. This results in smooth shift operation.

NGAT0180

NGAT0180S01

AT-26

OVERALL SYSTEM

Control Mechanism (Cont’d)

SAT003J

SAT004J

Normal Control

The line pressure to throttle opening characteristics is set for suitable clutch operation.

Back-up Control (Engine brake)

If the selector lever is shifted to “2” position while driving in D4(OD)

, great driving force is applied to the clutch inside the trans-

or D

mission. Clutch operating pressure (line pressure) must be increased to deal with this driving force.

During Shift Change

The line pressure is temporarily reduced corresponding to a change in engine torque when shifting gears (that is, when the shift solenoid valve is switched for clutch operation) to reduce shifting shock.

NGAT0180S0101

NGAT0180S0102

NGAT0180S0103

SAT005J

At Low Fluid Temperature

I Fluid viscosity and frictional characteristics of the clutch facing

change with fluid temperature. Clutch engaging or band-contacting pressure is compensated for, according to fluid temperature, to stabilize shifting quality.

I The line pressure is reduced below 60°C (140°F) to prevent

shifting shock due to low viscosity of automatic transmission fluid when temperature is low.

NGAT0180S0104

SAT006J

IDX

AT-27

Control Mechanism (Cont’d)

SAT007J

OVERALL SYSTEM

I Line pressure is increased to a maximum irrespective of the

throttle opening when fluid temperature drops to −10°C (14°F). This pressure rise is adopted to prevent a delay in clutch and brake operation due to extreme drop of fluid viscosity at low temperature.

SHIFT CONTROL

The shift is regulated entirely by electronic control to accommodate vehicle speed and varying engine operations. This is accomplished by electrical signals transmitted by the revolution sensor and throttle position sensor. This results in improved acceleration performance and fuel economy.

NGAT0180S02

Shift solenoid valve

A ON (Closed) OFF (Open) OFF (Open) ON (Closed) ON (Closed) B ON (Closed) ON (Closed) OFF (Open) OFF (Open) ON (Closed)

SAT008J

1,21,11

Control of Shift Solenoid Valves A and B

NGAT0180S0201

The TCM activates shift solenoid valves A and B according to signals from the throttle position sensor and revolution sensor to select the optimum gear position on the basis of the shift schedule memorized in the TCM. The shift solenoid valve performs simple ON-OFF operation. When set to ON, the drain circuit closes and pilot pressure is applied to the shift valve. [Relation between shift solenoid valvesA and B and gear positions]

Gear position

D2,22,1

Control of Shift Valves A and B

D4(OD) N-P

NGAT0180S0202

AT-28

SAT047J

OVERALL SYSTEM

Control Mechanism (Cont’d)

Pilot pressure generated by the operation of shift solenoid valves A and B is applied to the end face of shift valves A and B. The drawing above shows the operation of shift valve B. When the shift solenoid valve is “ON”, pilot pressure applied to the end face of the shift valve overcomes spring force, moving the valve upward.

LOCK-UP CONTROL

The torque converter clutch piston in the torque converter is locked to eliminate torque converter slip to increase power transmission efficiency. The solenoid valve is controlled by an ON-OFF duty signal sent from the TCM. The signal is converted to oil pressure signal which controls the torque converter clutch piston.

Conditions for Lock-up Operation

When vehicle is driven in 4th gear position, vehicle speed and throttle opening are detected. If the detected values fall within the lock-up zone memorized in the TCM, lock-up is performed.

Overdrive control switch ON OFF Selector lever “D” position Gear position D Vehicle speed sensor More than set value Throttle position sensor Less than set opening

NGAT0180S03

NGAT0180S0301

SAT010J

Closed throttle position switch OFF A/T fluid temperature sensor More than 40°C (104°F)

Torque Converter Clutch Solenoid Valve Control

The torque converter clutch solenoid valve is controlled by the TCM. The plunger closes the drain circuit during the OFF period, and opens the circuit during the ON period. If the percentage of OFF-time increases in one cycle, the pilot pressure drain time is reduced and pilot pressure remains high. The torque converter clutch piston is designed to slip to adjust the ratio of ON-OFF, thereby reducing lock-up shock.

OFF-time INCREASING

Amount of drain DECREASING

Pilot pressure HIGH

Lock-up RELEASING

NGAT0180S0302

SAT011J

IDX

AT-29

Control Mechanism (Cont’d)

OVERALL SYSTEM

Torque Converter Clutch Control Valve Operation

NGAT0180S0303

SAT048J

Lock-up Released

The OFF-duration of the torque converter clutch solenoid valve is long, and pilot pressure is high. The pilot pressure pushes the end face of the torque converter clutch control valve in combination with spring force to move the valve to the left. As a result, converter pressure is applied to chamber A (torque converter clutch piston release side). Accordingly, the torque converter clutch piston remains unlocked.

Lock-up Applied

When the OFF-duration of the torque converter clutch solenoid valve is short, pilot pressure drains and becomes low. Accordingly, the control valve moves to the right by the pilot pressure of the other circuit and converter pressure. As a result, converter pressure is applied to chamber B, keeping the torque converter clutch piston applied. Also smooth lock-up is provided by transient application and release of the lock-up.

OVERRUN CLUTCH CONTROL (ENGINE BRAKE CONTROL)

Forward one-way clutch is used to reduce shifting shocks in downshifting operations. This clutch transmits engine torque to the wheels. However, drive force from the wheels is not transmitted to the engine because the one-way clutch rotatesidle. This means the engine brake is not effective. The overrun clutch operates when the engine brake is needed.

Overrun Clutch Operating Conditions

D position D 2 position 2 1 position 1

Gear position Throttle opening

1,D2,D3

gear position

1,22

gear position At any position

1,12

Less than 3/16

NGAT0180S04

NGAT0180S0401

AT-30

SAT014J

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