Bendix Commercial Vehicle Systems GEN 5 ABS User Manual

Page 1

Bendix® Gen 4™ and Gen 5™ ABS for Trucks, Tractors, and Buses

SD-13-4746

Cab-Mounted Models

GEN 4™ AND GEN 5™ ABS INTRODUCTION

This manual describes both the cab mount and the frame mount versions of the Bendix® Gen 4™ and Gen 5™ Antilock Brake System/Automatic Traction Control (ABS/ATC) systems.

Both cab and frame mount versions are designed for:

• Tractors

• Trucks

• Buses and

• Motor Coaches and

• RVs. This manual covers:

• ABS/A TC Operation

• System Components

• Service Procedures

• Diagnosis and

• Troubleshooting Procedures. For information on disassembly , installation, and service of

related axle and brake components, refer to their individual Bendix Service Manuals.

For assistance in your area call Bendix at 1-800-247-2725 or RoadRanger® at 1-800-826-4357.

These ABS controllers and systems were originally marketed by Eaton Corporation under the Eaton® brand name. For more information contact Bendix, your local authorized Bendix dealer, or RoadRanger®.

Frame-Mounted Model

FIGURE 1 - Bendix® ABS Controller Assemblies

Table of Contents

ABS Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

ABS Component Function . . . . . . . . . . . . . . . . . . . . . . 3

ABS Indicator Lamp . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

ABS Trailer Indicator Lamp . . . . . . . . . . . . . . . . . . . . . 3

Automatic Traction Control (ATC) System . . . . . . . . . . 4

Component Overview . . . . . . . . . . . . . . . . . . . . . . . . . 5

Electronic Control Units (ECUs) . . . . . . . . . . . . . . . . . 7

ABS Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Modulator Valve Operation Modes . . . . . . . . . . . . . . . 10

Optional Front Axle Modules . . . . . . . . . . . . . . . . . . . 11

Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Troubleshooting Procedures . . . . . . . . . . . . . . . . . . . 13

System Configurations . . . . . . . . . . . . . . . . . . . . . . . 15

ServiceRanger PC Software . . . . . . . . . . . . . . . . . . . 16

Test Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Reading Configuration Codes . . . . . . . . . . . . . . . . . . 18

Retrieving Diagnostic Trouble Codes . . . . . . . . . . . . . 18

Clearing Diagnostic Trouble Codes and/or System

Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Disabling ATC for Dyno Testing . . . . . . . . . . . . . . . . . 20

Speed Sensor Troubleshooting . . . . . . . . . . . . . . . . . 25

The 17•12 Sensor Memory Diagnostic Trouble Code 26

Wheel End Speed Sensor Repair . . . . . . . . . . . . . . . 28

Pressure Modulator V alve (PMV) T roubleshooting . . 30

ABS Modulator Valve . . . . . . . . . . . . . . . . . . . . . . . . . 33

Automatic Traction Control (ATC) V alve

Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Performance Test of the Relay Valve . . . . . . . . . . . . . 34

ATC Valve Removal . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Cab Mount ECU Pin Identification . . . . . . . . . . . . . . . 39

Frame Mount ECU Pin Identification . . . . . . . . . . . . . 43

Document Revision Level

This document is subject to revision. For updates, please visit www.bendix.com.

Eaton®, RoadRanger®, and ServiceRanger® are registered trademarks of Eaton Corporation.

Page 2

ANTILOCK BRAKING SYSTEM (ABS)

ABS-controlled braking ensures optimum vehicle stability while minimizing the stopping distance. During vehicle operation, the ABS Electronic Control Unit (ECU) continuously monitors all wheel speed sensors. Data input from the wheel speed sensors allows the ECU to:

• Detect impending wheel lock.

• Maintain optimum wheel slip during braking.

• Maximize vehicle stability while maintaining braking effectiveness.

ABS Operation

The ABS controls braking by operating the Pressure Modulator V alves. The ECU makes a new assessment of conditions and updates the control signal to the pressure modulator valves at the rate of 100 times per second.

Braking force

remains at

optimum level

Speed sensors

monitor wheel

rotation

When inactive, the pressure modulator valves provide straight-through-passages for supply air to the brake chambers. During ABS operation (an ABS “event”), the control unit operates the valves to override the supply of air to the chambers. During an ABS release, supply air is held off while the chambers are vented to the atmosphere. In hold mode, supply air is held off and chamber air is held constant. When required, air is applied to the chamber at a controlled rate by modulating the hold side of the modulator valve.

The ABS system itself does not apply additional braking power. Rather , the purpose of ABS is to limit brake torque to prevent locking that results in loss of lateral stability and increased stopping distances. Cautious driving practices such as maintaining adequate distances from the vehicle ahead are still essential to safe vehicle operation.

Speed signal

to ECU

Hold and release solenoids control

air pressure inthe

brake chambers

FIGURE 2 - Overview of ABS Operation

Electronic Control Unit(ECU)

interprets speed signals

and activates valves

Sensors on

all configured wheels

signal status toECU

Page 3

ABS Component Function

The ABS system operates as follows (see Figure 2).

1. Speed sensors on each wheel monitor wheel rotation.

2. Each speed sensor communicates wheel rotation pulses to the central Electronic Control Unit (ECU).

3. The ECU receives speed sensor input, interprets the signal pulses, and calculates speed and acceleration rates for the wheels and the vehicle.

4. Based on speed sensor input with the brakes applied, the ECU detects impending wheel lock and operates the ABS modulator valves as required for proper control. The modulator valves can be operated in either a release or a hold mode to regulate air pressure in the brake chambers.

5. Braking force is applied at a level which minimizes stopping distance while maintaining as much lateral stability as possible.

FIGURE 3 - ABS Indicator Lamps

ABS Indicator Lamp

This lamp is the primary indicator of the ABS status.

• The ABS lamp illuminates steadily for a two second bulb-check whenever the switched ignition is ON. The ABS lamp turns OFF after the bulb-check if there are no ABS malfunctions present.

• The ABS lamp flashes on and off continuously when the off-highway mode is selected. (Special option for military and off-highway vehicles.)

• If the Indicator Lamp remains ON, after the bulb-check, there is an ABS diagnostic trouble code that requires service.

NOTE: In the case of a speed sensor failure which has been corrected, the indicator lamp will remain on until sensor output has been verified by the control unit. In this case it is necessary to move the vehicle above 5 mph before the indicator lamp will turn off.

ABS Trailer Indicator Lamp

Tractor/Towing vehicles manufactured on or after March 1, 2001 are equipped with a cab mounted “ABS Trailer” indicator lamp.

When an ABS equipped trailer with Power Line Carrier (PLC) communications capability is connected to the tractor , the ABS T railer indicator lamp will illuminate for a two second bulb check after the ignition is switched on. The ABS lamp turns OFF after the bulb-check if there are no ABS malfunctions present on the trailer ABS.

If the trailer is NOT equipped with ABS or ABS with PLC capability , the ABS trailer indicator lamp in the cab will not illuminate.

Page 4

Automatic Traction Control (ATC) System

The ATC system is available on all Standard ABS ECU’s. ATC is not availa ble on Basic ECU’s. It helps improve traction on slippery or unstable driving surfaces by preventing excessive wheel spin. ATC also enhances vehicle stability by prevention of power spin-out.

A TC requires:

1. ATC valve - Either a stand alone valve or a Rear Axle V alve Assembly with integral A TC solenoid may be used.

2. SAE J1922 or J1939 engine interface (the ABS ECU serial data interface must match the engine controller interface).

3. Brake Light Switch input.

4. ATC Indicator Lamp.

The Electronic Control Unit (ECU) must be configured for ATC operation either by using the diagnostic switch, an MPSI ProLink

hand-held tester or Eaton’s ServiceRanger

PC software.

A TC Operation

During periods of wheel slip, the Electronic Control Unit enters an Automatic Traction Control mode. There are various modes of Automatic Traction Control.

Thermal (Brake Heat) Protection

T o prevent excessive brake and drum temperature resulting from brake activity , A TC incorporates a brake temperature estimation algorithm to determine when differential braking mode should be suspended. The differential braking function is re-enabled after a cool-down period.

A TC Indicator Lamp

The ATC indicator lamp operates when a vehicle is equipped with the optional Automatic T raction System.

• Gen 4™ ABS – Lights at key-ON and remains lit with A TC inactive until the driver presses the brake pedal.

• Gen 5™ ABS – Light s at key-ON and turns of f af ter a 2 second lamp check. A TC is active after the lamp check.

• Flashes rapidly to indicate that ATC is active.

• Flashes slowly when the “mud-and-snow” mode is selected and then flashes more rapidly when the automatic traction control system operates.

• Remains ON if an engine data link failure occurs.

NOTE: Some non-ATC equipped vehicles have an ATC lamp that is labeled as a spin light. It indicates when a low traction condition has been encountered. No control action is taken.

System operation:

• At speeds above 25 mph, the engine is throttled back via the SAE J1922 or SAE J1939 data link to control spin out.

• At speeds below 25 mph, both engine control and differential brake control are activated as required to control wheel slip. Once triggered, differential braking mode remains active regardless of vehicle speed.

• An optional mud and snow switch allows greater wheel spin (more torque) when activated. It is intended for adverse conditions, usually off-highway. Except for special cases, the switch is programmed for momentary operation. ATC reverts to normal operation when the switch is cycled a second time and whenever the system goes through a power-up cycle.

Component Function

When brake control is utilized, the ATC valve is activated, diverting supply tank air to the Modulator Valves on the drive axle(s). The Electronic Control Unit then activates the appropriate solenoids in order to apply a brake force to the spinning wheel. The Automatic Traction Control System cannot increase traction to a particular wheel; it can only utilize the available traction.

FIGURE 4 - ATC Indicator Lamp

Page 5

Component Overview

Bendix ABS components include:

• Electronic Control Unit (ECU): The ECU monitors and controls the ABS. It also diagnoses ABS malfunctions and stores specific diagnostic trouble codes.

• Pressure Modulator Valve (PMV): This component regulates brake chamber air pressure. It houses the hold and release solenoids. A modulator valve is located near each brake chamber or pair of brake chambers that make up an ABS controlled wheel site.

• Rear Axle V alve Assembly: An assembly made up of two pressure modulator valves and a relay valve.

• Wheel End Speed Sensor: Single point variable reluctance (magnetic) sensor that generates an alternating voltage signal in response to the movement of teeth on a tone wheel.

• ABS Lamp (Yellow): This indicator lamp, located on the driver instrument panel, warns the driver of ABS malfunctions. It is also capable of blinking diagnostic fault codes when the ECU is in the self-diagnostic mode.

• In-Cab ABS Trailer Lamp: This indicator lamp, located on the driver instrument panel, warns the driver of trailer ABS malfunctions. It is not capable of blinking diagnostic trouble codes.

• A TC Valve: The traction control valve applies full system pressure to the relay valve during traction control operation to provide differential (side to side) braking at controlled drive axles.

• ATC Lamp: This indicator lamp, located on the driver instrument panel, lights to indicate loss of traction which is being managed by the Automatic Traction Control System.

• Relay/Breaker Panel: The OEM provides two circuit breakers and either one or two relays as part of the ABS. One relay is used for indicator lamp control. A second (optional) relay may be used to control a retarder and/or lockup torque converter.

• Diagnostic Port Connector: The diagnostic port connector is an industry standard connector that is used to connect to the J1587 diagnostic link. This connector also provides power and ground for diagnostic test equipment.

Page 6

FIGURE 5 - ABS Components

Page 7

Electronic Control Units (ECUs) Identification

Frame mount ECUs are environmentally packaged versions of the related Gen 4™ & Gen 5™ ABS cab-mounted units (Standard, Basic). The circuitry and software is the same.

™

Gen 5 hardware. ECUs are available in 4 and 6-channel versions with either J1922 or J1939 data links. There is also a 24volt version. Further service information is available on www.bendix.com.

ABS units incorporate power line carrier (PLC)

Bendix Part Number

Date Code

Serial Number

FIGURE 6 - Electronic Control Unit Identification Tags

Cab Mount

Serial Number

Frame Mount

Date Code

Page 8

300XXX

Designedand Manufacturedby

0 486 104 036 Made inGermany

MFOEO798O313

™™

Gen 4 & Gen 5 ABS - Basic Cab Mount

BOSCH

862

300XXX

ndManufacturedby

Designeda

0 486 104 036 MadeinGermany

MFOEO798O

BOSCH

862

313

™

Gen 5 ABS– Standard Cab Mount

Blank

Connector

™

Gen 5 ABS(PLC - Basic Frame Mount)

FIGURE 7 - Available Bendix ABS Electronic Control Units

™

Gen 4 ABS– Standard Cab Mount

Sliding Lock

ECU Cover

ECU Connector

(1 of4)

™™

Gen 4 & Gen 5 ABS – Standard Frame Mount

Page 9

ABS Valves

The ABS modulator valve controls air pressure to individual brake assemblies. Depending on the particular ABS configuration, a system may utilize three, four or six modulator valves. See Figure 8.

Each modulator valve contains two air control solenoids, which act as pilots to the hold and release diaphragms. The hold solenoid blocks inlet air to brake chambers; the release solenoid removes pressure from the brake. The 3-pin threaded connector has pins for the hold and release solenoid and a third, common terminal.

Rear Axle Valve Assemblies

Rear Axle Valve Assemblies are available for some applications depending on OEM preferences. They are combinations of two modulator valves and a relay valve. The assemblies are available in 4.0 and 5.5 PSIG versions, with or without an integral ATC solenoid.

1/2 NPT

Inlet Port

Twist-Lock Connector

Exhaust Port

1/2 NPT

Inlet Port

FIGURE 8 - Modulator Valve

1/2 NPT

Delivery Port

1/2 NPT

Delivery Port

Threaded

Connector

Exhaust Port

ATCVersion

Standard Version

FIGURE 9 - Rear Axle Valve Assemblies, 4-Port ABS and ABS/ATC Versions Shown

Page 10

Vents

Solenoid

Inlet

Exhaust

FIGURE 10 - Normal Apply and ABS/ATC Apply

Inlet

Hold Diaphragm

Outlet

Release Diaphragm

Outlet

Inlet Zero

Pressure

Outlet

Exhaust

FIGURE 11 - Normal Release

Inlet

Outlet

Exhaust

FIGURE 12 - ABS/ATC Hold

Modulator Valve Operation Modes

1. Apply–Air flows straight through valve. Hold diaphragm

is vented to allow air flow. Inlet pressure feeds behind release diaphragm to block the exhaust port. No solenoids are activated.

2. Normal Release–With quick release function, hold diaphragm is vented and there is no pressure at the inlet port. Air is allowed to flow from outlet to inlet. Since release diaphragm is not pressurized, air also flows out the exhaust port. No solenoids are activated.

Exhaust

FIGURE 13 - ABS/ATC Release

3. ABS/ATC Hold–The hold solenoid is activated. Both diaphragms are pressurized. No air flows through the valve.

4. ABS/ATC Release–Both solenoids are activated. The hold diaphragm is pressurized, blocking the inlet air. The release diaphragm is vented, allowing air to flow from the outlet port back through the exhaust port.

Page 11

Optional Front Axle Modules

An optional front axle module is available. It is an assembly of two modulator valves and a quick release valve. Three crack pressure settings are available:

• 0-1 PSIG

• 3-4 PSIG

• 6-8 PSIG.

FIGURE 14 - Front Axle Module

Tone Ring

Speed Sensors

Each wheel of an axle under direct ABS control is monitored by a speed sensor. S peed sensors for drive axles and steer axles may be different styles and installed in different locations.

Wheel End Sensors

For most applications, Bendix ABS uses standard wheel end sensors (see figure 15). The front sensor is accessible on the inboard side of the steering knuckle. The rear drive axle sensor is accessible by removing the wheel and drum assembly.

Wheel-end sensors are conventional, single point, variable reluctance sensors. These are often referred to as "magnetic sensors" or "magnetic pickups." These sensors consist of a rod or pole piece surrounded by a coil of wire. A magnet is closely coupled to the pole piece and circulates a magnetic field through the coil. As the teeth of the tone ring rotate past the pole piece, the resistance (reluct ance) to the magnetic field varies. The variable reluctance causes variations in the magnetic field which in turn induce a varying voltage in the coils which are wound around the pole piece.

Some general characteristics of variable reluctance, magnetic sensors are:

• The output voltage decreases as the air gap increases.

• The output voltage increases with the speed of the teeth past the pole piece.

• The output voltage waveform is independent of the direction of wheel rotation.

Wheel-End Sensors are protected with stainless steel metal sheaths. They are designed to fit within beryllium-copper friction sleeves which give them a self-adjustment feature.

Wheel End Speed Sensor

Drive and Steer Axles

Right angle version shown

Straight version also available

FIGURE 15 - Sensor Assembly

Wheel End

Sensor

Standard

Page 12

Speed Sensor

FrontAxle

Pressure

Modulator Valve

Electrical Layout

Indicator Lamps

ABS TractorIndicator Lamp (IL)

ABS TrailerIL (after 3/1/01)

ATCLamp (whenATC equipped)

Electronic Control

Diagnostic Connector

Diagnostic Switch

ABS OffRoadSwitch (optional)

ATCMud & Snow Switch (optional)

RearAxle

ValveAssembly

Unit (ECU) Cab Mountor Frame Mount

TractionControlValve

StandAlone or Integral with

RearAxle ValveAssembly

Pneumatic Layout

Brake

Chamber

Treadle

Quick

Release

Valve

SteerAxle

Modulator Valve

FIGURE 16 - Typical Electrical and Pneumatic Layouts

Relay Valve

Control Supply

ATCValve

Pressure ModulatorValve

Brake

Chambers

Anti-Compounding

Relay /Quick

Release Valve

Page 13

DIAGNOSTICS

An important feature of Bendix ABS is the system diagnostic capability. This section describes how to retrieve configuration information and error codes to troubleshoot ABS system diagnostic trouble codes. There are three ways to retrieve and display ABS configuration information and trouble codes:

• ServiceRanger PC software: Displays configuration information and diagnostic trouble codes on the PC monitor. Refer to the ServiceRanger PC software information later in this section.

• ProLink hand-held tester: Displays configuration information and diagnostic trouble codes on the handheld tester display. Refer to the hand-held tester information later in this section.

• Diagnostic switch: Flashes configuration code and diagnostic trouble codes on the ABS indicator lamp. Refer to page 18 for operation of the diagnostic switch.

Fault Codes

WARNING! PLEASE READ AND FOLLOW THESE INSTRUCTIONS TO AVOID PERSONAL INJURY OR DEATH:

When working on or around a vehicle, the following general precautions should be observed at all times.

1. Park the vehicle on a level surface, apply the

parking brakes, and always block the wheels. Always wear safety glasses.

2. Stop the engine and remove ignition key when

working under or around the vehicle. When working in the engine compartment, the engine should be shut off and the ignition key should be removed. Where circumstances require that the engine be in operation, EXTREME CAUTION should be used to prevent personal injury resulting from contact with moving, rotating, leaking, heated or electrically charged components.

3. Do not attempt to install, remove, disassemble or

assemble a component until you have read and thoroughly understand the recommended procedures. Use only the proper tools and observe all precautions pertaining to u se of those tools.

4. If the work is being performed on the vehicle’s air

brake system, or any auxiliary pressurized air systems, make certain to drain the air pressure from all reservoirs before beginning ANY work on the vehicle. If the vehicle is equipped with an AD-IS™ air dryer system or a dryer reservoir module, be sure to drain the purge reservoir.

5. Following the vehicle manufacturer’s recommended procedures, deactivate the electrical system in a manner that safely removes all electrical power from the vehicle.

6. Never exceed manufacturer’s recommended pressures.

7. Never connect or disconnect a hose or line containing pressure; it may whip. Never remove a component or plug unless you are certain all system pressure has been depleted.

8. Use only genuine Bendix® replacement parts, components and kits. Replacement hardware, tubing, hose, fittings, etc. must be of equivalent size, type and strength as original equipment and be designed specifically for such applications and systems.

9. Components with stripped threads or damaged part s should be replaced rather than repaired. Do not attempt repairs requiring machining or welding unless specifically stated and approved by the vehicle and component manufacturer.

10. Prior to returning the vehicle to service, make certain all components and systems are restored to their proper operating condition.

11. For vehicles with Antilock Traction C ontrol (ATC), the ATC function must be disabled (ATC indicator lamp should be ON) prior to performing any vehicle maintenance where one or more wheels on a drive axle are lifted off the ground and moving.

Troubleshooting Procedures

Figure 17 shows an organized approach to troubleshooting ABS trouble codes. Follow the steps listed below to locate and correct ABS component and wiring problems.

1. Check that the ABS ECU configuration corresponds to

the ABS components installed on the vehicle. Reconfigure the ECU if the configuration does not match the installed ABS components.

2. Access active diagnostic trouble code(s). Inactive

(historical) diagnostic trouble codes are also reported and may provide additional information to aid in troubleshooting.

3. Look up the code description, the possible causes and

the repair procedures provided in this section.

4. Perform the recommended repair procedures.

5. After the repairs are completed, clear all codes and

check for any additional codes.

Page 14

Cycle ignition key

OFF to ON

ObserveABS

indicator lamp operation

Lamp turns OFF after 2 second lamp check

ABS system not reporting

Codes–perform traditional

foundation brake

troubleshooting and repair

Activate blink codes

with diagnostic button

Check ECU configuration

Indicator lamp

blinking when activated

with diagnostic

button?

YES

Lamp stays ON

Select EatonABS diagnostic tool

Use Service Ranger diagnostic software

Check ECU configuration

Does tester

communicate with

ECU?

YES

Does configuration

information agree

with available

hardware?

Lamp never ON

Check for power to ABS ECU.

Check indicator lamp and wiring

Use MPSI ProLink tool

Check J1587 data link wiring

Reconfigure ECU

Check power circuit

for ECU

Reconfigure ECU

FIGURE 17 - Antilock Brake System Troubleshooting Chart

YES

Read trouble codes and descriptions

Takecorrectiveaction

Clear active and inactive trouble codes

Is this a trailer

ECU?

Recheck trouble codes after clearing.

If indicator lamp remains lit

and 17-12 trouble code is set,

drive vehicle to clear and turnoff

indicator lamp.

YES

Recheck trouble codes after clearing.

If indicator lamp remains lit

and no trouble codes are set,

drive vehicle to turn off

indicator lamp.

Page 15

SYSTEM CONFIGURA TIONS

Available Configurations

A wide variety of system configurations are available (refer to Figure 17). It is important to be able to read system configurations and to be able to properly reconfigure a system when necessary .

When to Configure

ECUs are factory configured for the most common requirements. Basic systems are setup for 4s-4m operation with retarder control via retarder relay. Standard systems are setup for 6s-4m operation with retarder control via engine data link. For applications other than these factory configurations (for example use of a retarder control relay , 4s-3m operation, 6s-6m operation or traction control), it is necessary to perform a configuration or “setup” process. This process sets up the ECU for the components that are installed so that proper control and fault tolerance will be

Fault Codes

Tone Ring

Wheel SpeedSensor (WSS)

implemented. The diagnostic switch, MPSI Pro-Link® tool or ServiceRanger PC software may be used to configure to a higher level (add components or functionality). If it is desired to move the configuration downward (fewer components than standard), the ProLink tool or ServiceRanger PC software must be used.

How to Configure

Use the “SYSTEM SETUP” menu with the MPSI ProLink tool, the diagnostic switch (refer to page 25 for procedure) or ServiceRanger PC software. Use of the “SETUP” function will also clear inactive trouble codes from the system. However it is recommended that the “CLEAR TROUBLE CODES” function be used for clearing inactive codes.

Verification

It is important to verify that the intended configuration has been obtained. Refer to Figure 20 (page 17) for proper interpretation of configuration blink codes.

RearAxle

ValveAssembly

Pressure

Modulator

Valve

(PMV)

4S -4M

6S -6Mw/ATC

ATC

Valve

FIGURE 18 - Typical ABS Configurations

6S -4Mw/ATC

Page 16

Test Equipment

Bendix recommends the use of the following products to troubleshoot the ABS system:

• A multimeter or digit al volt-ohmmeter (DVOM).

• Eaton ServiceRanger PC software or an MPSI ProLink hand-held tester.

Multimeter

A multimeter can be used to check:

• Speed sensor circuit resistance.

• PMV and ATC valve solenoid resistances.

• ABS power circuit voltages.

• Engine data link voltages.

• Retarder control relay .

• Wiring harness diagnostic trouble codes.

ServiceRanger PC Software

ServiceRanger PC software can be used to read and clear error codes and obtain a short description of failures. The software can initiate test sequences for controller outputs and can also read system data such as voltage at the

ECU, wheel speeds and cutout speeds. CAUTION: Eaton ServiceRanger PC software can activate

output tests for all output devices. Since these tests can affect operation of the vehicle braking system, the ECU incorporates special safety protection. One axle must show zero speed or the test will be halted.

ServiceRanger

Software CD

Laptop PC

1. Monitor Data

Wheel Speeds Cut-Out Speeds Input Voltages Switch States

Deutsch HD-10

Connector

Serial Communicator

Interface

2. Retrieve TroubleCodes

Retrieve Trouble Codes Clear Trouble Codes

To Diagnostic

Connector

PCINTERF

ACE

ServiceRanger Main MenuOptions

1. Monitor Data

2. Retrieve DiagnosticTroubleCodes

3.Advanced Product Functions

4. Product Downloads

3. Adv. Prod.Functions

TestValves TestLights TestRetarderControl

4. Product Downloads Read ECU Configuration Configure ECU DisableATC

FIGURE 19 - ServiceRanger Menus & Hardware Setup

Page 17

Hand-Held Tester

An MPSI ProLink® hand-held tester with Bendix proprietary cartridge can be used to read and clear error codes and obtain a short description of failures. The tester can initiate test sequences for controller outputs and can also read system data such as voltage at the ECU, wheels speeds and cutout speeds. A st andard heavy duty truck cartridge may also be used, but cannot initiate test sequences.

CAUTION: The ProLink hand-held tester can activate output tests for all output devices. Since these tests can affect operation of the vehicle braking system, the ECU incorporates special safety protection. One axle must show zero speed or the test will be halted.

Release

Button

Eaton

Applications

Applications Card

Fault Codes

MPC™ Cartridge

Bendix

MPSI Pro-Link

Deutsch HD-10

Connector

Diagnostic

Connector

Diagnostic and

Power Cable

Eaton ABS

Press Enter

1. System INFO

2. Trouble codes

3. Monitor Data

4. Component Test

5. System Set-up

6. ATC Disable

7. English/Metric

8. Exit

1. System INFO

Part No. Date Serial No. Software No. System Configuration

–ABS

– ATC Steer Wheel Size Rear Wheel Size Rear-Rear Wheel Size MIC Parameter

2. Trouble Codes

Actual Trouble Codes

Extended Trouble Codes

Clear Memory

3. Monitor Data

Wheel Speeds Cut out Speeds System Volts Input Switches

FIGURE 20 - Hand-Held Tester Menus and Set-Up

4. Component Test

ValveRoutines TCV WL TCL RET Interface

5. System Setup

System Config

6. ATC Disable

For Dyno Test

7. English/Metric

8. Exit

Page 18

Diagnostic Switch

Blink Codes – System Configuration and System Faults. By properly actuating the ABS diagnostic button,

configuration codes and diagnostic trouble codes can be retrieved as blinked sequences on the ABS indicator lamp. Configuration codes are sequences of four blinked digits while diagnostic trouble codes appear as two blinked numbers. Refer to the charts beginning on page 19 for a description of these codes. T o perform any of the activities listed below, simply follow the step s as given. If you make a mistake during one of the steps, stop and start over at the beginning of the procedure.

All blink codes are displayed by the ABS indicator lamp only . The ATC lamp does not display blink codes.

Note: Before attempting any repairs:

1. Retrieve the configuration codes and diagnostic trouble codes (write them down).

2. Reconfigure the ECU if the configuration does not agree with the installed hardware. The ECU cannot be configured downward (components removed) with the diagnostic button. For example, a 6S-4M cannot be configured to 4S-4M. Downward configurations require the use of a ProLink tool or ServiceRanger software.

3. If the configuration is correct, clear the diagnostic trouble codes. The process for clearing the trouble codes and reconfiguring the ECU is the same when using the diagnostic button.

4. Once again retrieve the diagnostic trouble codes. Only active codes will now be displayed.

Retrieving Diagnostic Trouble Codes

• Turn the ignition key to “ON.”

• If vehicle is equipped with A TC, apply and release brakes once before proceeding.

• Press and hold the diagnostic button for two seconds and release.

• Two-number blink codes are retrieved and displayed.

2 Sec

Reading Configuration Codes

• Turn the ignition key to “ON.”

• Press and hold the diagnostic button for two seconds and release.

• Without pause, press the diagnostic button a 2nd time for two seconds and release.

• Four-digit configuration code is retrieved and displayed.

2 Sec 2 Sec<1S

Page 19

Blink Code

Sequence

1st

VOLTAGE CONFIGURATIONS

Flashes Description

1 12 Volt System 2 24 Volt System

1.5 Sec. Pause

2nd

4.5 Sec. Pause

3rd

1.5 Sec. Pause

4th

ABS CONFIGURATIONS

Flashes Description

Fault Codes

2 4 Sensors/4Modulator Valves 3 4 Sensors/3Modulator Valves 6 6 Sensors/4Modulator Valves 8 6 Sensors/6Modulator Valves 9 6 Sensors/5Modulator Valves

– SelectLow Steer

RETARDERCONFIGURATIONS/INTERAXLE

Flashes Engine Interface Retarder RelayControl Interaxle LockControl

1 (5) NO NO NO (YES) 2 (6) YES NO NO (YES) 3 (7) YESNO NO (YES) 4 (8) YES YES NO (YES)

ATCCONFIGURATIONS

Flashes Engine Control Brake Control

2 NO NO 3 N/A N/A 4 N/A N/A 5 YES YES

FIGURE 21 - Reading ABS Configuration Codes

Page 20

Clearing Diagnostic Trouble Codes and/or System Configuration

• With the ignition “OFF” press and hold the diagnostic button.

• Turn the ignition key to “ON” while pressing the diagnostic button.

• Wait two seconds and release the diagnostic button.

• Press and release the brake pedal.

• ECU is reconfigured to match connected components and diagnostic trouble codes are cleared.

• Repeat the “Retrieving Diagnostic Trouble Codes” procedure to verify that the trouble codes are cleared.

2 + Sec

Disabling ATC for Dyno T es ting

• Turn the ignition key to “ON.”

• Press and hold the diagnostic button for at least 3 seconds and release.

• ATC light turns “ON” and ABS light blinks 17 • 8 indicating A TC is disabled.

• At the next ignition cycle ATC will be reactivated.

3+ Sec

First TroubleCode

first half ofcode

1.5 second pause

second half ofcode

FIGURE 22 - Typical Blink Code Report

4.5

second

pause

Additional TroubleCodes

first half ofcode

1.5 second pause

second half ofcode

4.5 second pause

Sequence continues until all troublecodes are reported.

Page 21

Blink Codes

1st. 2nd.

11 –/– No Trouble Found 21 001/000 Sensor air gap too large. Left Steer Sensor 22 001/008 Air gap too large or sensor shorted. 23 001/010 Speed Sensor signal is noisy. 24 001/008 Wheel locked too long during an ABS cycle. 25 001/008 High deceleration rate at wheel site or sensor shorted. 26 001/012 Sensor shorted low or high or sensor open. 27 001/012 Internal error at the sensor port of the ECU. 28 001/002 Sensor in the wrong location for the system configuration. 31 002/000 Sensor air gap too large. Right Steer Sensor 32 002/008 Air gap too large or sensor shorted. 33 002/010 Speed Sensor signal is noisy. 34 002/008 Wheel locked too long during an ABS cycle. 35 002/008 High deceleration rate at wheel site or sensor shorted. 36 002/012 Sensor shorted low or high or sensor open. 37 002/012 Internal error at the sensor port of the ECU. 38 002/002 Sensor in the wrong location for the system configuration. 41 003/000 Sensor air gap too large. Left Rear Sensor. 42 003/008 Air gap too large or sensor shorted. 43 003/010 Speed Sensor signal is noisy. 44 003/008 Wheel locked too long during an ABS cycle. 45 003/008 High deceleration rate at wheel site or sensor shorted. 46 003/012 Sensor shorted low or high or sensor open. 47 003/012 Internal error at the sensor port of the ECU. 48 003/002 Sensor in the wrong location for the system configuration. 51 004/000 Sensor air gap too large. Right Rear Sensor. 52 004/008 Air gap too large or sensor shorted. 53 004/010 Speed Sensor signal is noisy. 54 004/008 Wheel locked for too long during an ABS cycle. 55 004/008 High deceleration rate at a wheel site or sensor shorted. 56 004/012 Sensor shorted low or high or sensor open. 57 004/012 Internal error at the sensor port of the ECU. 58 004/002 Sensor in the wrong location for the system configuration.

MID 136

SID/FMI

Fault Codes

Description

Location

Page 22

Blink Codes

1st. 2nd.

61 005/000 Sensor air gap too large. Left Rear Sensor. 62 005/008 Air gap too large or sensor shorted. 63 005/010 Speed Sensor signal is noisy. 64 005/008 Wheel locked for too long during an ABS cycle. 65 005/008 High deceleration rate at wheel site or sensor shorted. Left Rear Sensor. 66 005/012 Sensor shorted low or high or sensor open. (continued). 67 005/012 Internal error at the sensor port of the ECU. 68 005/002 Sensor in the wrong location for the system configuration. 71 006/000 Sensor air gap too large. Right Rear Sensor. 72 006/008 Air gap too large or sensor shorted. 73 006/010 Speed Sensor signal is noisy. 74 006/008 Wheel locked too long during an ABS cycle. 75 006/008 High deceleration rate at wheel site or sensor shorted. 76 006/012 Sensor shorted low or high or sensor open. 77 006/012 Internal error at the sensor port of the ECU. 78 006/002 Sensor in the wrong location for the system configuration. 81 007/003 Short circuit from the release solenoid to voltage. Left Steer Axle PMV. 82 007/004 Short circuit from the release solenoid to ground. 83 007/005 Open circuit at the release solenoid. 84 007/005 Open circuit on the common line to the valve. 85 007/003 Short circuit from the hold solenoid to voltage. 86 007/004 Short circuit from the hold solenoid to ground. 87 007/005 Open circuit at the hold solenoid. 88 007/002 System configuration is incorrect. 8 10 151/014 Inter-axle differential control circuit shorted high. IAD Circuit. 8 10 151/014 Inter-axle differential control circuit shorted low or open. 91 008/003 Short circuit from the release solenoid to voltage. Right Steer Axle PMV. 92 008/004 Short circuit from the release solenoid to ground. 93 008/005 Open circuit at the release solenoid. 94 008/005 Open circuit on the common line to the valve. 95 008/003 Short circuit from the hold solenoid to voltage. 96 008/004 Short circuit from the hold solenoid to ground. 97 008/005 Open circuit at the hold solenoid. 98 008/002 System configuration is incorrect.

MID 136 SID/FMI

Description

Location

Page 23

Blink Codes

1st. 2nd.

10 1 009/003 Short circuit from the release solenoid to voltage. Left Rear Axle PMV. 10 2 009/004 Short circuit from the release solenoid to ground. 10 3 009/005 Open circuit at the release solenoid. 10 4 009/005 Open circuit on the common line to the valve. 10 5 009/003 Short circuit from the hold solenoid to voltage. 10 6 009/004 Short circuit from the hold solenoid to ground. 10 7 009/005 Open circuit at the hold solenoid. Left Rear Axle PMV (cont.).

10 8 009/002 System configuration is incorrect. 10 or 11 9 014/003 Common side of valves – stray voltage detected. PMV Commons. 10 or 11 10 014/003 Common side of valves shorted high. 10 or 11 11 014/004 Common side of the valves shorted to ground.

11 1 010/003 Short circuit from the release solenoid to voltage. Right Rear Axle PMV. 11 2 010/004 Short circuit from the release solenoid to ground. 11 3 010/005 Open circuit at the release solenoid. 11 4 010/005 Open circuit on the common line to the valve. 11 5 010/003 Short circuit from the hold solenoid to voltage. 11 6 010/004 Short circuit from the hold solenoid to ground. 11 7 010/005 Open circuit at the hold solenoid.

11 8 010/002 System configuration is incorrect. 12 1 011/003 Short circuit from the release solenoid to voltage Left Rear Axle PMV. 12 2 011/004 Short circuit from the release solenoid to ground. 12 3 011/005 Open circuit at the release solenoid. 12 4 011/005 Open circuit on the common line to the valve. 12 5 011/003 Short circuit from the hold solenoid to voltage. 12 6 011/004 Short circuit from the hold solenoid to ground. 12 7 011/005 Open circuit at the hold solenoid. 12 8 011/002 System configuration is incorrect. 13 1 012/003 Short circuit from the release solenoid to voltage. Right Rear Axle PMV. 13 2 012/004 Short circuit from the release solenoid to ground. 13 3 012/005 Open circuit at the release solenoid. 13 4 012/005 Open circuit on the common line to the valve. 13 5 012/003 Short circuit from the hold solenoid to voltage. 13 6 012/004 Short circuit from the hold solenoid to ground. 13 7 012/005 Open circuit at the hold solenoid. 13 8 012/002 System configuration is incorrect.

MID 136

SID/FMI

Fault Codes

Description

Location

Page 24

Blink Codes

1st. 2nd.

14 5 018/003 Solenoid in ATC valve shorted high. ATC Valve. 14 6 018/004 Solenoid in ATC valve shorted to ground. 14 7 018/005 ATC valve open circuit. 14 8 018/002 ATC valve found when it should not be present. 14 12 249/002 or 231/002 Time-out or no connection to engine link (J1922/1939). Data Link. 15 1 254/012 ECU internal trouble code. ECU. 15 2 253/012 ECU internal trouble code. 15 3 253/013 ECU internal trouble code. 15 4 253/012 ECU internal trouble code. ECU (cont.). 15 5 254/002 ECU internal trouble code. 15 6 254/002 ECU internal trouble code. 15 7 254/002 ECU internal trouble code. 15 8 253/013 ECU internal trouble code. 15 9 231/012 ECU internal trouble code. 15 10 254/012 ECU internal trouble code. 15 11 254/012 ECU internal trouble code. 16 1 or 5 251/004 Excessive voltage on PMV Power. Power Circuits. 16 2 or 6 251/003 Low voltage found on PMV Power. 16 3 or 7 251/005 No voltage found on PMV Power. 16 4 or 8 251/005 Open circuit found on PMV Ground. 16 9 251/004 Excessive voltage found on ECU Power. 16 10 251/003 Low voltage found on ECU Power. 16 11 251/002 Voltage difference between PMV Power inputs is too high. 17 1 013/003 Retarder control relay shorted high or open circuit. 17 2 013/004 Retarder control relay shorted to ground. 17 3 249/002 or 231/002 J1922/1939 date link not functioning. 17 4 249/002 or 231/002 J1922/1939 date link time out. 17 5 253/013 Tire size, front to rear out of range. 17 6 253/013 Tire size out of range or parameter fault. 17 7 — Brake light switch not pushed at this power cycle. 17 8 — ATC system is disabled for dynamometer test. 17 10 023/014 Indicator lamp circuit is faulty. 17 12 151/014 Sensor memory bit set, (A sensor trouble code has

MID 136 SID/FMI

Description

occurred, the ECU must read wheel speeds on all wheels to clear this trouble code.)

Location

Page 25

Speed Sensor Troubleshooting

Follow the steps listed below to locate and correct sensor related ABS trouble codes.

1. Access active trouble code(s) using either the Blink Code procedure, with ServiceRanger or the Hand-held Tester procedure.

2. Lookup the code description, the possible causes and the repair procedures provided in this section.

3. Perform the recommended repair procedures.

4. After the repairs are completed, clear all codes and check for any additional codes.

5. If a sensor related trouble code has occurred, a code 17•12 will remain in the system until the vehicle has been driven.

Fault Codes

FIGURE 23 - Typical Wheel Speed Sensor Circuit

TOP- Looking intoharness connector

1 2 3

Harness Connector PIN Circuit Description

B (6-Way) 4 SpeedSensor (+)Left Steer

5 SpeedSensor (-)Left Steer

C (9-Way) 4 SpeedSensor (+)Right Steer

5 SpeedSensor (-)Right Steer

D (15-Way) 5 SpeedSensor (+)Left Rear

6 SpeedSensor (-)Left Rear 8 SpeedSensor (+)Right Rear

9 SpeedSensor (-)Right Rear E (12-Way) 5 SpeedSensor (+)Left RearRear 6-channel 6 Speed Sensor (-) Left Rear Rear

Only 8 SpeedSensor (+)Right RearRear

9 SpeedSensor (-)Right RearRear

Not Used On BasicSystem

7 8

17 18

ABCDE

9 10 11 12

X1 Grey

X2 Black

X3 Green

5 4

6 5 4 3 2 1

X4 Brown

Harness Connector PIN Circuit Description

X2 (Black) 5 Speed Sensor(-) Right Steer

6 SpeedSensor (+)Right Steer 7 SpeedSensor (-)Left Steer 8 SpeedSensor (+)Left Steer

X3 (Green) 1 SpeedSensor (-)Left Rear

2 SpeedSensor (+)Left Rear 3 SpeedSensor (-)Right Rear 4 SpeedSensor (+)Right Rear

X4 (Brown) 3 Speed Sensor(-) Left Rear Rear 6-channel 4 Speed Sensor(+) LeftRear Rear

Only 5 SpeedSensor (-)Right RearRear

6 SpeedSensor (+)Right RearRear

Not Used On BasicSystem

Speed Sensor ResistanceTest The correct resistanceforthespeed sensor circuit is between 950 ohmsand1900ohms. Measure resistance atthewheellocation to check the speed sensor. Measure resistance attheappropriateECU harness connector pins to check thecableandspeed sensor. Note: Refer tothechartfor pin identification.

FIGURE 24 - Wheel Speed Sensor Harness Circuit Descriptions and Resistance Test

Page 26

The 17•12 Sensor Memory Diagnostic Trouble Code

The ABS indicator lamp indication and 17•12 diagnostic trouble code are provided to remind the service technician of the need to verify the performance of the ABS wheel speed sensors by driving the vehicle after servicing the sensors. ABS wheel speed sensors do not generate signals unless the wheels are turning. Because of this, certain sensor codes can only be detected when the vehicle is in motion.

The trouble code 17•12 is generated after the initial sensor codes are cleared. The ABS indicator lamp remains lit. The trouble codes must be rechecked after clearing the sensor codes in order to see 17•12 reported.

A 17•12 trouble code and ABS indicator lamp signal for sensor code cannot be cleared using a ProLink, ServiceRanger software or the diagnostic button. They can only be cleared by driving the vehicle. The ABS ECU will clear the 17•12 blink code and turn off the ABS indicator lamp when all active sensor code issues are resolved and the vehicle is driven above 5 mph. The ABS ECU must detect speeds at all monitored wheels for the condition to clear.

Procedure:

1. Check trouble codes.

2. Troubleshoot and eliminate causes for all trouble codes.

3. Clear trouble codes.

4. Check trouble codes again (17•12 will be reported if sensor codes are cleared).

5. If 17•12 error code is reported, drive vehicle above 5 mph (ABS indicator lamp will go out and 17•12 trouble code will be cleared after a short period if all sensor signals are acceptable).

Note: If sensor codes still exist, the ABS indicator lamp will remain lit. The trouble codes will be logged once again after driving the vehicle. If more than one sensor site is affected, the codes may not be re-logged by the ECU until the vehicle has been driven and held above 20 mph for 35 minutes.

For more detailed troubleshooting, monitor the wheel speeds and cut-out speeds with ServiceRanger or a ProLink hand-held diagnostic tool. Troubleshoot and repair any speed sensor not reporting a wheel speed or showing a high cut-out speed.

Cut-out speeds are an indication of the strength of the sensor signal to the ECU and are proportional to air gap. Cut-out speeds should be in the range of 3-8 mph. Lower numbers indicate a stronger and better signal than higher numbers. High values indicate a sensor with an unreliable or non-existent signal.

Page 27

Blink Code

Sequence

Flashes Location

1st

1.5 Sec. Pause

2nd

2 LeftSteer 3 RightSteer 4 LeftRear 5 RightRear 6 LeftRear Rear 7 RightRear Rear

Fault Codes

Flashes Condition

1 Sensorair gap toolarge.

2 Airgap too largeor sensor

3 Speedsensor signal isnoisy.

shorted.

Action

If necessary, clean andlubricatesensor. Press intomountinghole until itbottoms against tone wheel. Cleartrouble code andverifythat code iscorrected by testdriving the vehicle. The indicator lampwill remain onuntilproper sensor outputis detected eventhough the code has been cleared.

Check sensor resistance.If sensor resistanceisout of range,replace sensor. Clean and lubricate sensor. Press intomounting hole untilitbottoms against tonewheel. Clear trouble code and verifythat code iscorrectedby test drivingthe vehicle.The indicatorlamp will remain on until propersensor output isdetectedeven though thecode has beencleared. Use approved lubricant.

Examine tone ringfor damage. Replacetonering and/or hubif necessary. Check wheel bearing adjustment. Adjust wheelbearings if necessary. Cleartrouble code andverifythat code is corrected bytest driving thevehicle.The indicator lampwill remain onuntil proper sensor output is detectedeven though thecodehas been cleared.

4 Wheellocked for excessive

period of timeduring an ABS cycle.

5 Excessiverate of deceleration

found at awheel site.

6 Sensorconnection shorted lowor

high or sensoris open.

7 Thereis an internalerror at the

sensor port ofthe ECU.

8 Asensorhas been foundin the

wrong location.

Check mechanical functionof brake. Checkforkinked or restrictedhoses. Clear troublecode and verify thatcode is correctedbytest driving thevehicle.The indicator lampwill remain on until proper sensoroutput is detectedeventhough the codehas been cleared.

Check for damagedtone ring orexcessiverun out. Repairtone ring and/oradjust wheel bearings. Clear troublecode and testdrivethe vehicle. The indicator lampwill remain onuntil proper sensor outputis detected eventhoughthe trouble codehas been cleared.

Use an ohmmeter to verifypropersensor resistance (Fig24). Check harnessfor shorts or opens. Repair harnessand/or replace sensorasnecessary.Clear trouble codeand verify that code is correctedby test drivingthevehicle. sensor output isdetected even thoughthetrouble code hasbeen cleared.

Clear trouble codeand test drivethevehicle. Theindicator lamp willremain on untilproper sensor output isdetected even thoughthecode has beencleared. If troublecode recurs, or cannot be cleared,replace ECU.

Check the controlunit configuration andverifythat sensors arewired in theproper location for the configuration(Refer to Schematic).

FIGURE 25 - Speed Sensor Diagnostic Trouble Code Troubleshooting Guide

The indicator lampwill remain onuntilproper

Page 28

Wheel End Speed Sensor Repair Front Axle Speed Sensor

The front axle speed sensor is located on the inboard side of the steering knuckle.

CAUTION: Block wheels before beginning this procedure. Follow all standard safety procedures, outlined by , but not limited to, the General Precautions listed on page 13 of this document.

CAUTION: Do not work under a vehicle supported by a jack.

Removal

1. Disconnect sensor cable from harness.

2. Remove the sensor from the sensor bushing. (Do not pull on cable.)

3. Remove the speed sensor friction sleeve from the steer knuckle.

Sensor

Friction Sleeve

ABS

Sensor

Bushing

Installation

1. Install the sensor bushing with the flange stops towards the inboard side of the vehicle.

2. Apply high-temperature silicon-base d grease to the body of the speed sensor .

3. Push the speed sensor completely into sensor bushing by hand until it stops against the tone ring. The speed sensor is properly installed and adjusted when it is touching the tone ring.

NOTE: The speed sensor must slide freely in and out of the mounting sleeve bore. Operating the vehicle with seized components will damage the speed sensor and the tone ring.

4. T est the installation.

5. Check the cable routing and connections.

6. Clear the trouble codes. A 17•12 trouble code will

remain in the system until the vehicle has been driven.

7. T est drive the vehicle and verify that the ABS warning lamp operates properly .

FIGURE 26 - Front Speed Sensor Components

Push

Sensor

FIGURE 27 - Wheel Speed Sensor Installation

Page 29

Rear Axle Speed Sensor

The rear axle speed sensor located inside the brake drum and is only accessible by removing the wheel and drum assembly.

NOTE: For diagnostic and service information on in-axle speed sensors, please contact Dana Corporation.

CAUTION: Block wheels before beginning this procedure. Follow all standard safety procedures, outlined by , but not limited to, the General Precautions listed on page 13 of this document.

CAUTION: Do not work under a vehicle supported by a jack.

Removal

1. Back off the slack adjuster to release the brake shoes.

2. Remove the wheel and tire assembly from the axle.

3. Remove the brake drum.

4. Remove the speed sensor with bushing from the mounting block on the axle housing. Use twisting motion and avoid pulling on the cable.

5. Disconnect any fasteners that hold sensor cable to other components and disconnect the speed sensor from the harness.

Fault Codes

Sensor

Friction Sleeve

Sensor Block

Installation

1. Install the sensor bushing with the flange stops toward the inboard side of the vehicle.

2. Apply a non-conductive grease lubricant to the body of the speed sensor.

3. Push the speed sensor completely into sensor bushing by hand until it stops against the tone ring. The speed sensor is properly installed and adjusted when it is touching the tone ring.

NOTE: The speed sensor must slide freely in and out of the mounting sleeve bore. Operating the vehicle with seized components will damage the speed sensor and the tone ring.

4. Route the cable to the frame.

5. Connect sensor cable to harness and install fasteners to hold the sensor cable in position.

6. Install the brake drum on the wheel hub.

7. Adjust the rear axle brakes.

8. Install the wheel and tire assembly and tighten the wheel nuts.

9. Test the inst allation.

10.Check the cable connections.

11. Clear the trouble codes. A 17•12 trouble code will remain

in the system until the vehicle has been driven.

12.Test drive the vehicle and verify that the ABS indicator lamp operates properly .

FIGURE 28 - Rear Speed Sensor Components

Page 30

Pressure Modulator Valve (PMV) Troubleshooting

Follow the steps listed below to locate and correct ABS modulator valve problems.

1. Access active trouble code(s) using either the Blink Code procedure or the hand-held tester procedure.

2. Lookup the code description, the possible causes and the repair procedures provided in this section.

3. Perform the recommended repair procedures.

4. After the repairs are completed, clear all codes and check for any additional codes.

ECU

FIGURE 29 - Typical PMV Circuit

Relay

Valve

Connection

Common

Release

1 32

Hold

Twist-LockConnector

Twist-Lock

Connector

Common

PMV Resistance Test

Measure resistance at the PMV location to check the valve.

Hold

Threaded

Connector

FIGURE 30 - PMV Harness Circuit Descriptions and Resistance Test

Looking IntoValve

Threaded Connector

Release

Measure resistance at the appropriate ECU harness connector pins to check the cable and valve.

Note: Refer to the chart for pin identification.

Measure Measure Resistance From: To: Range:

Common Hold 3-8 Ohms Common Release 3-8 Ohms HoldRelease 6-16 Ohms

Page 31

Cab Mount Frame Mount

TOP– Looking into harnessconnector

Harness Connector PIN Circuit Description

B (6-Way) 1 PMV 1(Release) Left Steer

2 PMV1 (Hold)Left Steer 3 PMV1 CommonLeft Steer

C (9-Way) 7 PMV 2 (Release)Right Steer

8 PMV2 (Hold)Right Steer

Fault Codes

9 PMV2 CommonRight Steer

D (15-Way) 1 PMV3 (Release) Left Rear

2 PMV3 (Hold)Left Rear 3 PMV3 CommonLeft Rear

D (15-Way) 10 PMV4 (Release)Right Rear

11 PMV4 (Hold)Right Rear 12 PMV 4 CommonRight Rear

E (12-Way) 1 PMV5 (Release)Left RearRear

6-channel 2 PMV5 (Hold)Left Rear Rear

Only 3 PMV 5 Common LeftRear Rear

E (12-Way) 10 PMV 6(Release) Right RearRear

6-channel 11 PMV 6(Hold) RightRear Rear

Only 12 PMV 6Common RightRear Rear

7 8

ABCDE

11 12

X1 Grey

X2 Black

X3 Green

6 5 4 3 2 1

X4 Brown

Harness Connector PIN Circuit Description

X2 (Black) 2 PMV1 (Hold) Left Steer

10 PMV 1 (Release)Left Steer 11 PMV1 CommonLeft Steer

X2 (Black) 3 PMV2 (Release) Right Steer

4 PMV2 (Hold)Right Steer 9 PMV2 CommonRight Steer

X3 (Green) 10 PMV 3 (Release)Left Rear

12 PMV 3 (Hold)Left Rear 11 PMV3 CommonLeft Rear

X3 (Green) 7 PMV 4 (Release)Right Rear

9 PMV4 (Hold)Right Rear 8 PMV4 CommonRight Rear

X4 (Brown) 10 PMV 5(Release) LeftRear Rear

6-channel 12 PMV 5 (Hold)Left RearRear

Only 11 PMV5 CommonLeft RearRear

X4 (Brown) 7 PMV 6(Release) Right Rear Rear

6-channel 9 PMV 6(Hold) Right Rear Rear

Only 8 PMV 6Common RightRear Rear

Not Used OnBasic System

FIGURE 31 - PMV Harness Circuit Descriptions and Resistance Test

Page 32

Blink Code

Sequence

1st

1.5 Sec. Pause

2nd

Flashes Location

8 PMV 1 Left Steer 9 PMV 2 Right Steer

10 PMV 3 Left Rear

Flashes Condition

1 There is ashort between the

2 The is ashortbetween the release

3 There is anopencircuit at the

4 There is anopencircuit in the 5 There is ashortbetween the hold

6 The is ashortbetween the hold

7 There is anopencircuit at thehold

8 Avalve has beenfoundwired in the

release solenoid and supplyvoltage.

solenoid and ground.

release solenoid.

common line to thevalve. solenoid and supply voltage.

solenoid and ground.

solenoid.

wrong location.

Flashes Location

11 PMV4 RightRear 12 PMV5 LeftRear Rear 13 PMV6 RightRear Rear

Action

Use multimeter to checkthat valve resistancesarecorrect. If valve is OKcheck harness forshortin wiring.

Use multimeter to checkthat valve resistancesarecorrect. If valve is OKcheck harness foropenin wiring.

Use multimeter to checkthat valve resistancesarecorrect. If valve is OKcheck harness forshortin wiring.

Use multimeter to checkthat valve resistancesarecorrect. If valve is OKcheck harness foropenin wiring.

Check the control unitconfiguration and verifythatvalves are wiredin the proper location for the configuration(Refer to Schematic).

Location

PMV Commons

Flashes

Condition

Stray voltage has beenfound on the common line of oneor more of the valves

Ashort to supplyvoltagehas been found on the commonline of oneor more of the valves

Ashort to ground hasbeen found on the common line ofone or moreof the valves

1st

1.5 Sec. Pause

Flashes

10 or 11

2nd

FIGURE 32 - PMV Diagnostic Trouble Code Troubleshooting Guide

Action

Unplug ECU and checkfor voltage onthePMV common pins.If voltage is found, repair harness. If noproblem is foundinharness, replace ECU.Note: Before replacing ECU clear troublecodes and verifythattrouble code isstill present (Refer to Schematic).

Unplug ECU and checkfor short to12volts on PMV commonpins. If any are shorted to supply, repair harness.If no short isfound in harness,replaceECU. Note: Before replacing ECU,clear trouble codesandverify that troublecode is still present (Refer toSchematic).

Unplug ECU and checkfor short togroundon PMV commonpins. If any are shorted to ground, repairharness. If noshortis found inharness, replace ECU. Note: Before replacing ECU,clear trouble codesandverify that troublecode is still present (Refer toSchematic).

Page 33

ABS Modulator Valve Removal

1. Turn ignition switch to the OFF position, and apply parking brake.

CAUTION: Block wheels before beginning this procedure. Follow all standard safety procedures, outlined by , but not limited to, the General Precautions listed on page 13 of this document.

2. Disconnect the wiring connector from the ABS valve.

3. Disconnect the air lines from the supply and delivery ports of the ABS valve.

4. Disconnect the valve mounting fasteners.

5. Remove the ABS valve.

NOTE: To service either modular valve or the relay valve, remove the entire assembly and then replace the individual components (valve).

Fault Codes

Installation

1. Install the valve. Torque fasteners to manufacturers specification.

2. Connect air lines.

• Supply to port 1 on valve.

• Service brake chamber to delivery port 2.

3. Connect the wiring connector to the ABS valve.

4. T est the inst allation:

• Modulator Valve Leak Test—Make and hold brake

application. No audible air leaks are permitted.

• Modulator Valve Component Test with Hand-Held

Diagnostic Tool—Select valve routines. Verify

proper valve location and operation with tool. Drive the vehicle and verify ABS indicator lamp operates properly.

5. Make several brake applications and check for prompt brake chamber applications and release at all wheels. Check the cable connections.

6. Clear codes.

7. Drive the vehicle and verify that the ABS indicator lamp operates properly .

Standard RearAxle

ValveAssembly

FIGURE 33 - Rear Axle Valve Assemblies – Standard and ATC Version Shown

ATCRearAxle

ValveAssembly

Page 34

Performance Test of the Relay Valve

CAUTION: Block wheels before beginning this procedure.

Follow all standard safety procedures, outlined by , but not limited to, the General Precautions listed on page 13 of this document.

1. Park vehicle on level surface and block wheels.

2. Release parking brake and fully charge the air system (governor cut out point).

3. Turn the engine OFF. Apply the service brake several times, then hold and check for prompt brake air chamber application and release at all wheels.

4. Apply brake, then hold. Coat outside of relay valve (where cover joins body) and connection between modulator valve and relay valve with a soap solution. No leakage is permitted.

5. If a sluggish response is noted at all wheels, inspect for kinked or obstructed air line leading to or from valve.

6. Increase system air pressure to governor cutoff. With the brakes released, coat exhaust port of relay valve with a soap solution. Leakage of a 1" bubble in 5 seconds is permissible.

7. Depress foot valve and keep depressed. Coat exhaust port with a soap solution. Leakage of a 1" bubble in 3 seconds is permissible.

Automatic T raction Control (ATC) V alve Troubleshooting

The following A TC troubleshooting pages provide the basic information necessary to: identify the diagnostic trouble code; locate the problem; review the possible cause(s); select the correct solution and utilize proper repair procedures.

Follow the steps listed below to locate and correct ATC problems.

1. Access active diagnostic trouble code(s) using either the Blink Code procedure or the hand-held tester procedure.

2. Lookup the code description, the possible causes and the repair procedures provided in this section.

3. Perform the recommended repair procedures.

4. After the repairs are completed, clear all codes and check for any additional codes.

Whether the ATC Valve is used as a stand-alone valve as shown in Figure 34 or is integrated into the cover of a relay valve as shown in Figure 33, the troubleshooting procedure is the same.

(1) TankAir

(2) Relayvalve

control line

(3) Treadle

FIGURE 34 - ATC Valve

Page 35

Cab Mount Frame Mount

TOP– Looking into harnessconnector

1 2 3

9 10 11 12

6 5 4 3 2 1

ABCDE

Harness Connector PIN Circuit Description

A(18-Way) 6 ATCMud and SnowSwitch

16 ATCL(ATCLight)

X1 Grey

Harness Connector PIN Circuit Description

X1 (Grey) 3 ATCL(ATC Light/ATCSwitch) X3 (Green) 5 ATCValve–

X2 Black

D (15-Way) 4 ATC Valve +

7 ATC Valve–

Fault Codes

ATCValveResistanceTest The correctresistancefor theATC Valvecircuit is between 9ohms and 15 ohms. Measure resistance at theATCValve tocheckthe valve. Measure resistanceatthe appropriate ECU harnessconnectorpins to check thecable and valve. Note: Refertothe chart for pinidentification.

FIGURE 35 - ATC Harness Circuit Descriptions and Resistance Test

Blink Code

Sequence

Flashes

Location

ATCValve

6 ATC valve+

X3 Green

X4 Brown

1st

Flashes

1.5 Second Pause

2nd

FIGURE 36 - ATC Diagnostic Trouble Code Troubleshooting Guide

Condition

Solenoid in ATC valve shorted high.

Solenoid in ATC valve shorted to ground.

ATCvalve open circuit.

ATCvalve found when itshouldnot be present.

Response

Use multimeter to checkthat valve resistances arecorrect (fig 34). If valve is OKcheck harness for openin wiring.

Verifyproper system configuration andcomponents. Clear faults. If error cannot becleared or recurs, replaceECU.

Page 36

A TC Valve Removal

CAUTION: Block wheels before beginning this procedure.

Follow all standard safety procedures, outlined by , but not limited to, the General Precautions listed on page 13 of this document.

1. Disconnect the wiring connector from the ATC valve.

2. Disconnect the air lines from the supply (port 1) and delivery port (port 2) and treadle (port 3) of the ATC valve.

3. Disconnect the valve mounting fasteners, and remove the valve.

Installation

1. Install the A TC valve. T orque fasteners to manufacturers specification.

2. Connect Air lines supply (port 1) delivery port (port 2) and treadle (port 3) of the ATC valve.

Blink Code

Sequence

3. Install the wiring connector to the ATC valve.

4. T est the inst allation.

• Traction Control Valve – Leak Test:

Make and hold brake application. No audible air leaks are permitted.

• Traction Control Valve Component Test with HandHeld Diagnostic Tool:

Select Traction Control Valve Verify T raction control light operation Drive the vehicle and verify ABS indicator lamp operates

properly. CAUTION: Do not start and engage the transmission with

one wheel raised from the floor. With A TC, power will go to the wheel on the floor and cause the vehicle to move. See page 20 to disable ATC for dyno testing.

1st

1.5 Sec. Pause

2nd

1st

1.5 Sec. Pause

Flashes

Location

ECU, Engine Interface

Flashes

Location

ECU

Flashes

No connection found toengine data link (J1922/J1939).

Condition

Action

Refer to electrical schematic.Check for properconnectionof data linktoECU. Verifythat polarity iscorrect.

Unplug connector at ECU.There should be avoltage between 0and2.5 volts on J1922/J1939 (–) and avoltage between 2.5and5 volts onJ1922/J1939(+).

If vehicle is notequipped with J1922/J1939enginelink, use diagnostictoolto reconfigure ECU.

Action

2nd

1–11

ECU Internal Fault

If fault cannot becleared, replace ECU.

FIGURE 37 - System and ECU Diagnostic Trouble Codes Troubleshooting Guide

Page 37

Blink Code

Sequence

Flashes

Location

1st

1.5 Sec. Pause

2nd

Fault Codes

Power Circuits

Flashes

1or5

2or6

3or7

4or8

Condition

Excessive voltage on PMVPower

Low voltage on PMVPower

No voltage found onPMV Power

Open circuit on PMVGround

Excessive voltage found on ECU Power

Low voltage found onECU Power

Action

Verifythat vehicle system voltageis OK (i.e.9to 16 volts).Ifvoltage is outof range, correct system problem.Unplug connector at ECUand turn onignition switch. If the voltageon PMV Power isdifferent than system voltage,repair wiring. Clear trouble codesand verify that theindicator lamp turnsoutafter bulb

check.

Unplug connector at ECUand check for continuityto ground onPMVGround. If continuity to ground isnot present, repair harness.

Verifythat vehicle system voltageis OK (i.e.9to 16 volts).Ifvoltage is outof range, correct system problem.Unplug connector at ECUand turn onignition switch. If the voltageon pin A-8 isdifferentthan system voltage,repairwiring. Clear trouble codes andverify that the indicatorlamp turns outafterbulb check.

check.

Voltagedifference between PMV Power inputs is toohigh

Verifythat vehicle system voltageis OK (i.e.9to 18 volts).Ifvoltage is outof range, correct system problem.Unplug connector at ECUand turn onignition switch. If the voltageon one PMV Powerpin differs from theother by greater than

0.5 volts, repair wiring.(Check circuit breakers and/orfuses on diagonalsupply line.) Clear trouble codesand verify that theindicator lamp turnsoutafter bulb

check.

FIGURE 38 - Power Circuit Diagnostic Trouble Codes Troubleshooting Guide

Page 38

Blink Code

Sequence

1st

1.5 Sec. Pause

2nd

Flashes

Location

Miscellaneous

Flashes

Condition

Retarder control relay shortedhigh or open circuit.

Retarder control relay shortedlow. or open circuit

J1922/1939 data link notfunctioning. (Retarder)

J1922/1939 data link timeout.

Tiresize, front torearout of range.

Tiresize out ofrangeor parameter fault.

Brake light switch notpushed at this power cycle.

ATCsystemis disabled for dynamometer test.

Warninglight short, loworopen

Sensor memory bit isset

Action

Use multimeter to verifyproper voltage at theretarder control relay.

Unplug connector at ECU.Thereshould be avoltagebetween 0 and 2.5 voltson J1939/J1922 (–) and avoltage between 2.5 and5.0 volts on J1939/J1922(+). Refer to schematic andcorrect wiring harness asrequired.

There is too greata difference in therollingradius of thefrontand rear tires. Steer axle tire radiuscannot be more than20% above rears or10%below.If the static loaded radius ofthe rear tires isoutside the range 15.9to21.5 inches the ECU must be recalibratedusing a diagnostic tool.

Press brake pedal. Iferror does not clear, checkfor missing connection atbrake light switch. If thebrake is not appliedyou should measure theresistanceof the brake light bulb (bulbbroken?). If the brakeis applied, you shouldmeasure vehicle system voltage. (i.e.9…16v)

Cycle ignition switch andATC willbe re-enabled.

Diagnostic switch may havebeen pressed for anexcessive period of time(>30 seconds). If not checkwiring associated with indicatorlamp.

This trouble code shouldclear when the vehicleis driven and theECUis able to read sensor outputvoltage. If this doesnothappen, verify thatthesensors are properly adjusted (pressed fullin to tone wheels.)

Note: Forcodes 17•3and 17•4 theproblem maybe within theengine controller,another controlleron the data linkor withinthe wiring orconnectors.

FIGURE 39 - Miscellaneous Diagnostic Trouble Codes Troubleshooting Guide

Page 39

Cab Mount ECU Pin Identification

This section shows how to identify Cab Mount ECU harness connectors and pin locations. The charts provide a brief description of the signal carried by each pin.

Looking IntoHarness Connector

Top

CDE

Fault Codes

Top

CDE

Top

CDE

Top

CDE

16 17 18

14 15

5 6

7 8 9

13 14

7 8 9

1 2

5 6

7 8

5 6

ConnectorA

18 -Way

Connector B

6 -Way

1 2

Connector C

9 -Way

Connector D

15 -Way

Top

CDE

FIGURE 40 - Cab Mount ECU – Connector Layout

Connector E

12 -Way

Page 40

ECU

CONNECTOR PIN DESCRIPTION

ECU

CONNECTOR PIN DESCRIPTION

A (18-Way) 1 J1922/J1939 -

™

2 Gen 4

ABS J1939 Shld/Gen 5™ ABS TIL 3 J1922/J1939 + 4 NC 5 Off Road ABS Switch (ORS) 6 ATC Mud & Snow Switch 7 Ignition, Switched 8 V Bat 2 9 V Bat 1

10 Ground - ECU 11 Ground - Diagonal 2 12 Ground - Diagonal 1 13 SAE J158714 SAE J1587+ 15 NC, Interlock 16 ATC Light 17 Retarder Relay 18 Indicator Lamp/Diagnostic Switch

B (6-Way) 1 PMV1 (Left Steer), Rel Solenoid

2 PMV1 (Left Steer), Hold Solenoid

3 PMV1 (Left Steer), Common 4 Speed Sensor 2 (Left Steer) + 5 Speed Sensor 2 (Left Steer) 6 Brake Light Switch

C (9-Way) 1 NC

2 NC 3 NC 4 Speed Sensor 3 (Right Steer) + 5 Speed Sensor 3 (Right Steer) 6 NC 7 PMV2 (Right Steer), Rel Solenoid

8 PMV2 (Right Steer), Hold Solenoid

9 PMV2 (Right Steer), Common

D (15-Way) 1 PMV3 (Left Rear), Rel Solenoid

2 PMV3 (Left Rear), Hold Solenoid

3 PMV3 (Left Rear), Common 4 ATC Valve 5 Speed Sensor 4 (Left Rear) + 6 Speed Sensor 4 (Left Rear) 7 ATC Valve + 8 Speed Sensor 5 (Right Rear) + 9 Speed Sensor 5 (Right Rear) -

10 PMV4 (Right Rear), Rel Solenoid

11 PMV4 (Right Rear), Hold Solenoid

12 PMV4 (Right Rear), Common 13 NC 14 NC 15 NC

E (12-Way) 1 PMV5 (Left Rear Rear), Rel Solenoid

2 PMV5 (Left Rear Rear), Hold Solenoid

3 PMV5 (Left Rear Rear), Common 4 NC 5 Speed Sensor 6 (Left Rear Rear) + 6 Speed Sensor 6 (Left Rear Rear) 7 NC 8 Speed Sensor 7 (Right Rear Rear) + 9 Speed Sensor 7 (Right Rear Rear) -

10 PMV6 (Right Rear Rear), Rel Solenoid

11 PMV6 (Right Rear Rear), Hold Solenoid

12 PMV6 (Right Rear Rear), Common

FIGURE 41 - Cab Mount ECU – Pin Identification Chart

Page 41

Fault Codes

FIGURE 42 - Gen 4™ and Gen 5™ Basic Cab Mount ABS Electrical Schematic

Page 42

FIGURE 43 - Gen 4™ and Gen 5™ Standard Cab Mount ABS Electrical Schematic

Page 43

Frame Mount ECU Pin Identification

This section shows how to identify Frame Mount ECU harness connectors and pin locations. The charts provide a brief description of the signal carried by each pin.

10 11 12

8 7 8 9

6 5 4 3 2 1

10 11 12

6 5 4 3 2 1

X2 Black

Fault Codes

10 11 12

X3 GreenX3 Green

7 8 9

6 5 4 3 2 1

10 11 12

7 8 9

6 5 4 3 2 1

X4 Brown

FIGURE 44 - Cab Mount ECU – Pin Identification Chart

X1 Grey

Page 44

X1 Grey

Pin Signal Description

X1-1 IGN X1-2 IGN

Ignition-1

Ignition-2 X1-3 ATCL ATC Light/ATC Switch X1-4 1587

J1587+

X1-5 RET Retarder Control X1-6 ENG X1-7 ENG X1-8 SHLD/TIL Gen 4 X1-9 1587

J1922/1939 Engine Control Link-

–

J1922/1939 Engine Control link+

™

ABS J1939 Shield/Gen 5™ ABS TIL

J1587-

–

X1-10 WL ABS WL/Diagnostic Switch X1-11 GND X1-12 GND

Ground

X2 Black X4 Brown

X3 Green

Pin Signal Description

X3-1 SS X3-2 SS X3-3 SS X3-4 SS

X3-5 ATCV X3-6 ATCV X3-7 REL X3-8 CMN X3-9 HLD X3-10 REL X3-11 CMN X3-12 HLD

Speed Sensor, Left RearSpeed Sensor, Left Rear+ Speed Sensor, Right RearSpeed Sensor, Right Rear+ Traction Control V alveTraction Control Valve+ Release Sol, Right Rear Common, Right Rear Hold Sol, Right Rear Release Sol, Left Rear Common, Left Rear Hold Sol, Left Rear

Pin Signal Description

X2-1 BLS Brake Light Switch X2-2 HLD X2-3 REL X2-4 HLD X2-5 SS X2-6 SS X2-7 SS X2-8 SS X2-9 CMN X2-10 REL X2-11 CMN

Hold Sol, Left Steer Release Sol, Right Steer Hold Sol, Right Steer Speed Sensor, Right SteerSpeed Sensor, Right Steer+ Speed Sensor, Left SteerSpeed Sensor, Left Steer+ Common, Right Steer Valve Release, Left Steer Valve Common, Left Steer Valve

X2-12 ORS Off Road Switch

FIGURE 45 - Frame Mount ECU – Pin Identification Chart

Pin Signal Description

X4-1 DLC X4-2 DLC X4-3 SS X4-4 SS X4-5 SS X4-6 SS X4-7 REL X4-8 CMN X4-9 HLD X4-10 REL X4-11 CMN X4-12 HLD

LRR

RRR

C+

RRR

LRR

Diff Lock ControlDiff Lock Control+ Speed Sensor Left Rear RearSpeed Sensor Left Rear Rear+ Speed Sensor Right Rear RearSpeed Sensor Right Rear Rear+ Release Sol, Right Rear Rear Common, Right Rear Rear Hold Sol, Right Rear Rear Release Sol, Left Rear Rear Common, Left Rear Rear Hold Sol, Left Rear Rear

Page 45

Fault Codes

FIGURE 46 - Gen 5™ Basic Frame Mount ABS Electrical Schematic

Page 46

FIGURE 47 - Gen 4™ and Gen 5™ Standard Frame Mount ABS Electrical Schematic

Frame Mount

Page 47

Glossary

ABS — Antilock Brake System. ABS Event — Impending wheel lock situation that causes the

ABS controller to activate the modulator valve(s).

Air Gap — Distance between the Sensor and tone ring. Anti-Compounding Valve — Prevents the application of the

service and spring brakes at the same time. Depending on vehicle design, the anti-compounding valve may be installed in combination with a relay valve or quick release valve.

Apply Timing — The time from the movement of the service

brake control for each brake chamber to reach 60 psi, with an initial service reservoir pressure of 100 PSI.

ASR — Automatic Slip Regulation. Another name for traction

control.

ATC — Automatic Traction Control. An additional ABS function

in which engine torque is controlled and brakes are applied differentially to enhance vehicle traction.

ATC Light — A light that indicates when traction control is

operating.

Channel — A controlled wheel site. CAN — Controller Area Network. J1939 is an SAE version of

the CAN link.

Clear Codes — System to erase historical faults from the ECU,

from either the Diagnostic Button or from a hand-held diagnostic tool (only repaired faults may be cleared).

Coefficient of Friction — The horizontal force required to move

a body (on a relatively smooth level surface) divided by the weight of the body.

Configuration — The primary objective is to identify a “normal”

set of sensors and modulators for the Electronic Control Unit, so that it will identify future missing sensors and modulators.

Crack Pressure — The ascending input pressure or input force

to an air valve required to initiate output pressure of flow.

Diagonal Control — ABS is configured with two diagonal circuits.

Diagonal control allows each control circuit to provide electrical control of modulator valves on opposite sides of the vehicle.

Diagnostic Connector — Diagnostic receptacle in vehicle cab

for connection of J1587 hand-held or PC based test equipment. The tester can initiate test sequences, and can also read system parameters.

Diagnostic Switch — A switch used to activate blinks codes. Diagnostic T rouble Code — A condition that interferes with the

generation or transmission of response or control signals in the vehicle's ABS system that could lead to the functionality of the ABS system becoming inoperable in whole or in part.

Differential Braking — Application of brake force to a spinning

wheel so that torque can be applied to wheels which are not slipping.

ECU — Electronic Control Unit. FMVSS-121 — Federal Motor Vehicle Safety Standard which

regulates air brake systems. Friction Sleeve — A beryllium copper sleeve which has fingers

cut into it. It is pressed between an ABS sensor and mounting hole to hold the sensor in place.

Indicator Lamp — An amber light which indicates the operating

status of an antilock system. When the indicator lamp is on, ABS is disabled and the vehicle reverts to normal brake operation.

Fault Codes

IR — Independent Regulation. A control method in which a wheel

is controlled at optimum slip, a point where retardation and stability are maximized. The brake pressure that is best for the wheel in question is directed individually into each brake chamber.

J1587 — The SAE heavy duty standard diagnostic data link. J1708 — An SAE standard which defines the hardware and

software protocol for implementing 9600 baud heavy vehicle data links. Both J1587 and J1922 are versions of J1708 data links.

J1922 — The SAE heavy vehicle data link which operates

according to J1708 protocol. It is generally used for ATC or automatic transmission interface to an engine.

J1939 — A high speed 250,000 baud data link which is expected

to replace J1922.

MIR— Modified Independent Regulation. A method of controlling

the opposite sides of a steer axle during ABS operation so that torque steer and stopping distance are minimized. Usually control begins at pure select low and moves towards independent control as the cycle progresses.

PLC — Power Line Carrier. The serial communication protocol

used to communicate with the trailer over the blue full time power wire.

PMV — Pressure Modulator Valve. An air valve which is used to

vent or block air to the brake chambers to limit or reduce brake torque.

QR — Quick Release. Quick release Valves allow faster release

of air from the brake chamber after a brake application. To balance the system, quick release valves have hold off springs that produce higher crack pressures (when the valves open).

Relay Valve — Increases the application speed of the service

brake. Installed near brakes with larger air chambers (type 24 or

30). The treadle valve activates the relay valve with an air signal. The relay valve then connect its supply port to its delivery ports. Equal length air hose must connect the delivery ports of the relay valve to the brake chambers.

Release Timing — The measurement in time from initial brake

movement to reach 5 psi with 95 psi initial pressure at the brake chambers.

Retarder Relay — A relay which is used to disable a retarder

when ABS is triggered.

Select High — A method of ABS control in which the brake torque

is released at several wheels when the last wheel begins to lock.

Select Low — The brake pressures level is the same on both

wheels of a given axle. The pressure level is based on the wheel which is running at the lower friction coefficient.

Select Smart — The difference in pressure between the left and

right brake chamber does not exceed a certain amount. This leads to the wheel which is running at the high friction coefficient being braked less strongly.

Sensor Bushing — A bushing which is pressed into steer axles

to hold a wheel speed sensor and friction sleeve.

Stored Faults — A Fault that occurred. TCS — Traction Control System, another name for ATC or ASR. T one Ring — A ring that is usually pressed into a wheel hub that

has a series of teeth (usually 100) and provides actuation for the speed sensor. Note maximum run out is .008.

Page 48