Anti-Lock Brake System (ABS) and Stability Control

Special Tool(s)

	Backprobe Pins POM6411 or equivalent
	Flex Probe Kit NUD105-R025D or equivalent
	Fluke 77-IV Digital Multimeter FLU77-4 or equivalent
	Rotunda Active Wheel Speed Sensor Tester 105-R0110
	Vehicle Communication Module (VCM) and Integrated Diagnostic System (IDS) software with appropriate hardware, or equivalent scan tool

Principles of Operation

Anti-Lock Brake System

The ABS module continuously monitors brake pedal input, lateral vehicle motion and the rotational speed of each wheel. The PCM sends the brake pedal switch information to the ABS module over the High Speed Controller Area Network (HS-CAN) while the Restraints Control Module (RCM) sends lateral acceleration sensor information to the ABS module over a private HS-CAN . Wheel speed information is retrieved by the ABS module using 4 active wheel speed sensors, one for each wheel. When the ABS module detects an impending wheel lock during a braking event, the ABS module modulates brake pressure to the appropriate brake caliper(s) by opening and closing the appropriate solenoid valves inside the Hydraulic Control Unit (HCU) while the hydraulic pump motor is activated. Once the affected wheel(s) return to the desired speed, the ABS module returns the solenoid valves in the HCU to their normal position.

The ABS module has 2 self-test options, one is carried out using a scan tool and the other is carried out when the ABS is initialized (ignition ON). During either self test the ABS module carries out a preliminary electrical check of the system sensors and activates the hydraulic pump motor for approximately one-half second. During this time, a buzzing or humming noise may be heard and a vibration may be felt in the brake pedal and is a normal condition. During the module initialized self test, the pump motor check is carried out at approximately 16 km/h (10 mph). Any malfunction detected in the system causes the module to set a DTC, disable the ABS function and send a message over the HS-CAN to the Instrument Panel Cluster (IPC) to illuminate the ABS warning indicator. However, the base hydraulic power-assist braking system will function normally.

Electronic Brake Distribution (EBD)

On initial application of the brake pedal, full pressure is applied to the rear brakes. The ABS module then uses wheel speed input to calculate an estimated rate of deceleration. Once vehicle deceleration exceeds a predetermined threshold, the ABS module closes the appropriate isolation valves in the HCU to hold the rear brake pressure constant while allowing the front brake pressure to build. This creates a balanced braking condition between the front and rear wheels and minimizes the chance of rear wheel lockup during hard braking. As the vehicle decelerates, the valves are opened to increase the rear brake pressure in proportion to the front brake pressure. A slight bump sensation may be felt in the brake pedal when EBD is active. If ABS is disabled due to DTCs being present in the ABS module, EBD continues to function unless the DTCs are for wheel speed sensors or the HCU . When EBD is disabled, the ABS warning indicator, the red brake warning light, stability/traction control indicator (sliding car icon) and the stability/traction control OFF indicator (sliding car OFF icon) illuminate.

AdvanceTrac®

The AdvanceTrac® system consists of the traction control function and the Electronic Stability Control (ESC) function.

Traction Control

The ABS module continuously monitors and compares the rotational speed of the drive wheels in relation to the non-driven wheels. When the drive wheels begin to spin faster than the non-driven wheels, the ABS module modulates brake pressure to the appropriate brake caliper(s) by opening and closing the appropriate solenoid valves inside the HCU while the hydraulic pump motor is activated. At the same time, the ABS module sends a message over the HS-CAN that a traction event is taking place. When the PCM receives this message, it assists with traction control by adjusting engine timing and decreasing fuel injector pulses. When the IPC receives this message, it flashes the sliding car icon. Once the driven wheel speed returns to the desired speed, the ABS module returns the solenoid valves in the HCU to their normal position, deactivates the hydraulic pump motor and sends another message over the HS-CAN indicating that the event has ended. The PCM returns engine timing and fuel injectors to normal operation and the IPC extinguishes the sliding car icon. After the vehicle speed exceeds 100 km/h (62.1 mph), traction control is accomplished only through the PCM torque control.

The traction control system can be disabled by the driver using the stability/traction control switch. When the driver disables the traction control function, the IPC communicates traction control system status to the ABS module via the HS-CAN . The ABS module takes no further action in regards to traction control until the driver activates the function or until the ignition is cycled from OFF to ON. The ABS module disables the traction control function if there are any wheel speed sensor or solenoid valve DTCs present in the ABS module. The traction control function is also disabled if there is a communication error between the ABS module and the PCM. When the traction control function is disabled, the ABS module sends a message to the IPC to illuminate the sliding car OFF icon.

Electronic Stability Control (ESC)

The ABS module continuously monitors the vehicle motion relative to the intended course. This is done by using sensors to compare the steering wheel input and the yaw rate sensor input with that of the actual vehicle motion. The Power Steering Control Module (PSCM) sends the steering wheel angle and rate of change information to the ABS module over the HS-CAN while the RCM sends yaw rate sensor information to the ABS module over a private HS-CAN . If the ABS module determines from the inputs that the vehicle is unable to travel in the intended direction, the ABS module modulates brake pressure to the appropriate brake caliper(s) by opening and closing the appropriate solenoid valves inside the HCU while the hydraulic pump motor is activated. At the same time, the ABS module sends a message over the HS-CAN that a vehicle stability event is taking place. When the PCM receives this message, it assists with vehicle control by adjusting engine timing and decreasing fuel injector pulses. When the IPC receives this message, it flashes the sliding car icon. Once the vehicle instability has been corrected, the ABS module returns the solenoid valves in the HCU to their normal position, deactivates the hydraulic pump motor and sends another message over the HS-CAN bus indicating that the event has ended. The PCM returns engine timing and fuel injectors to normal operation and the IPC extinguishes the sliding car icon.

The ESC function does not operate with the transmission in REVERSE. The ABS module disables the ESC function if there are any wheel speed sensor, stability sensor or steering angle sensor DTCs present in the ABS module. Also, if there is a communication error between the ABS module and the PSCM or the ESC function is disabled. When the ESC function is disabled, the ABS module sends a message over the HS-CAN to the IPC to illuminate the sliding car OFF icon.

Hill Start Assist

The ABS module uses the brake pedal switch message and ABS wheel speed sensor input to determine that the vehicle is at a complete stop. The transmission selector lever message lets the ABS module know that the vehicle is not being parked. The stability sensor messages from the RCM enable the ABS module to determine if the vehicle is on an incline greater than 5 degrees or greater than a 3% grade. The hill start assist function automatically engages once the above conditions have been met.

As the driver releases the brake pedal, the ABS module commands the HCU to close the isolation valves which will maintain the current brake system pressure, preventing the vehicle from rolling down the incline. Brake pressure is held for 2-3 seconds while the driver transitions to the accelerator pedal. As the accelerator pedal is pressed and the engine RPM increases, the ABS module gradually releases the brake pressure to make sure the vehicle is neither rolling back nor driving off until there is sufficient driving torque to move the vehicle.

Launch Control

The launch control system is controlled through the use of the launch control switch in the ride control switch pack and through the message center. When the launch control switch is pressed, a voltage signal is sent to the PCM. The PCM sends a message to the IPC over the HS-CAN indicating that the driver has requested launch control system activation. The driver then configures the launch control system through the message center, see the Owner's Literature for specific information. The launch control system will only activate when the AdvanceTrac® system is enabled or in Sport mode. Once activated, the launch control system will remain ON until the driver deactivates it, the system will not reset when the ignition is cycled.

Stability/Traction Control Switch

The stability/traction control switch is hardwired to the IPC . The IPC communicates switch status to the ABS module via the HS-CAN . The traction control switch allows the driver to control the AdvanceTrac® system. Traction control system status is indicated by the sliding car OFF icon and the message center in the IPC . The AdvanceTrac® system automatically restores to full functionality when the ignition is cycled from OFF to ON. There are 3 or 4 AdvanceTrac® system modes that can be selected, depending on the vehicle configuration and options.

• AdvanceTrac® enabled (both traction control and ESC functions are active)
• Traction control disabled ( ESC function remains active)
• AdvanceTrac® Sport (special calibration to enhance performance characteristics, not available on all vehicles)
• AdvanceTrac® disabled (both traction control and ESC systems are off)

The different modes of the AdvanceTrac® system can only be selected by starting with the AdvanceTrac® enabled. When a mode other than AdvanceTrac® enabled is selected, the sliding car OFF icon in the IPC illuminates. When the switch is pressed a single time, the traction control is disabled (traction control off mode); when the switch is pressed twice while the brake pedal is applied, AdvanceTrac® Sport mode is enabled; and when the switch is pressed and held for at least 5 seconds while the brake pedal is applied, the entire AdvanceTrac® system is disabled.

Pressing the switch once from any of the above-mentioned modes re-enables full AdvanceTrac® system operation. Also, at the start of every ignition cycle, full AdvanceTrac® system operation is present regardless of the mode selected on the previous ignition cycle (unless the vehicle is equipped with launch control and launch control is enabled). The conventional ABS cannot be disabled through the use of the stability/traction control switch.

Stability Control Sensors

The stability control sensors for the AdvanceTrac® system include the yaw rate sensor and the lateral accelerometer. The yaw rate sensor and the lateral accelerometer are able to detect and measure changes in vehicle direction that indicate the need for the ABS to make corrections that help prevent vehicle roll over or spin outs. The sensors are housed in the RCM which sends sensor information to the ABS module over the Controller Area Network (CAN). Install a new RCM if any of the sensors are damaged.

Steering Sensor

The steering sensor is used by the PSCM to determine speed and direction of the steering wheel. This information is transmitted to the ABS module along the HS-CAN . The sensor is attached to the Electronic Power Assist Steering (EPAS) column assembly and is not serviced separately.

ABS Module Calibration

When a new ABS module, HCU , or RCM is installed, the ABS module must be calibrated. The calibration procedure is required for the ABS module to learn the zero-position of the various ESC sensors and components.

If a DTC sets for any component of the ABS or AdvanceTrac® system, correct the fault condition and clear the DTC before carrying out the calibration procedure. The need to calibrate the ABS module is also indicated by the sliding car icon in the IPC flashing once every 2 seconds. The indicator flashes after clearing the DTCs associated with the ABS or AdvanceTrac® system.

To calibrate the ABS module, carry out the IVD Initialization sequence using the scan tool.

If a DTC is retrieved after calibration, refer to the ABS Module DTC Chart in this section.

Inspection and Verification

1. Verify the customer concern.

2. Verify the stoplamps operate correctly. If the stoplamps do not operate correctly, refer to Section 417-01 . If the stoplamps operate correctly, proceed to the next step.

3. Verify the base brake system operates correctly. If any concerns are present, address them before continuing with any ABS concerns. Refer to Section 206-00 . If the base brake system operates correctly, proceed to the next step.

4. Visually inspect for obvious signs of mechanical or electrical damage.

  Visual Inspection Chart

5. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.

6. NOTE: Make sure to use the latest scan tool software release.

   If the cause is not visually evident, connect the scan tool to the Data Link Connector (DLC).

7. NOTE: The Vehicle Communication Module (VCM) LED prove-out confirms power and ground from the DLC are provided to the VCM .

   If the scan tool does not communicate with the VCM :
   • check the VCM connection to the vehicle.
   • check the scan tool connection to the VCM .
   • refer to Section 418-00 , No Power To The Scan Tool, to diagnose no power to the scan tool.

8. If the scan tool does not communicate with the vehicle:
   • verify the ignition is ON.
   • verify the scan tool operation with a known good vehicle.
   • refer to Section 418-00 , The PCM Does Not Respond To The Scan Tool, to diagnose no response from the PCM.

9. Carry out the network test.
   • If the scan tool responds with no communication for one or more modules, refer to Section 418-00 .
   • If the network test passes, retrieve and record Continuous Memory Diagnostic Trouble Codes (CMDTCs).

10. Clear the CMDTCs and carry out the self-test diagnostics for the ABS module and the IPC .

11. If the DTCs retrieved are related to the concern, go to the ABS Module DTC Chart. For all other DTCs, refer to Section 419-10 .

12. If no DTCs related to the concern are retrieved, GO to Symptom Chart .

DTC Charts

NOTE: This module utilizes a 5-character DTC followed by a 2-character failure type code. The failure type code provides information about specific fault conditions such as opens or shorts to ground. Continuous Memory Diagnostic Trouble Codes (CMDTCs) have an additional 2-character DTC status code suffix to assist in determining DTC history.

 ABS Module DTC Chart

Symptom Chart

Pinpoint Tests

Pinpoint Test A: DTC B11E8:16

Refer to Wiring Diagrams Cell 42 , Vehicle Dynamic Systems for schematic and connector information.

Normal Operation
• DTC B11E8:16 (ABS Power Supply: Circuit Voltage Below Threshold) — this DTC sets in continuous memory and on demand if the voltage supplied to the ABS module falls below 10 volts during the ABS module self-test or normal operation.

This pinpoint test is intended to diagnose the following:
• Wiring, terminals or connectors
• Charging system concern
• Battery concern
• ABS module

PINPOINT TEST A: DTC B11E8:16

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector

NOTE: Failure to disconnect the battery when instructed results in false resistance readings. Refer to Section 414-01 .

Pinpoint Test B: DTC B11E8:17

Refer to Wiring Diagrams Cell 42 , Vehicle Dynamic Systems for schematic and connector information.

Normal Operation
• DTC B11E8:17 (ABS Power Supply: Circuit Voltage Above Threshold) — this DTC sets in continuous memory and on-demand if the voltage supplied to the ABS module exceeds 16 volts during the ABS module self-test or normal operation.

This pinpoint test is intended to diagnose the following:
• Charging system concern
• ABS module

PINPOINT TEST B: DTC B11E8:17

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

NOTE: DTC B11E8:17 may be stored in the module memory due to past battery charging or vehicle jump starting events.

Pinpoint Test C: DTCs C0020:12, C0020:15 and C0020:71

Refer to Wiring Diagrams Cell 42 , Vehicle Dynamic Systems for schematic and connector information.

Normal Operation

When the ignition key is turned to the ON position, the ABS module commands the Hydraulic Control Unit (HCU) pump on for 100 ms (±6 ms) and is then commanded off. After 6 ms, the ABS module reads the voltage that is being generated by the HCU pump. If the voltage indicates the motor is spinning at less than 500 rpm, there may be a locked motor. If this condition is detected 4 times, DTC C0020:12 sets. The pump motor is checked for an open circuit 2 seconds after the most recent successful pump motor off command. If the pump motor feedback remains greater than 0.75 volt for more than 50 ms (±6 ms) after these conditions have been met, DTC C0020:15 sets.

• DTC C0020:12 (ABS Pump Motor Control: Circuit Short To Battery) — sets in continuous memory and on-demand when the motor driver feedback voltage is less then battery voltage, that indicates an open driver or supply condition where the battery voltage is adjusted to the minimal threshold for the motor supply.
• DTC C0020:15 (ABS Pump Motor Control: Circuit Short To Battery Or Open) — sets in continuous memory and on-demand if the ABS pump feedback voltage is greater than 0.75 volts for more than 50 ms after the pump motor has been commanded off for 2 seconds or more, if there is an open or high resistance on the ABS pump motor circuit between the ABS module and the HCU , or if the ABS module is faulted internally.
• DTC C0020:71 (ABS Pump Motor Control: Actuator Stuck) — sets in continuous memory and on-demand if the ABS module detects that the ABS pump motor is not rotating when it is commanded to run.

This pinpoint test is intended to diagnose the following:
• Fuse
• Wiring, terminals or connectors
• HCU
• ABS module

PINPOINT TEST C: DTCs C0020:12, C0020:15 AND C0020:71

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

NOTE: Failure to disconnect the battery when instructed results in false resistance readings. Refer to Section 414-01 .

Pinpoint Test D: DTCs C0031:13, C0031:17, C0031:23 (LF), C0034:13, C0034:17, C0034:23 (RF), C0037:13, C0037:17, C0037:23 (LR), C003A:13, C003A:17 and C003A:23 (RR)

Normal Operation

The wheel speed sensors are active sensors and generate a square wave signal that is sent to the ABS module. When the ignition is turned to the RUN position, the ABS module carries out a self-test to determine if the sensors are functional. Voltage and ground are supplied to the front and rear wheel speed sensors from the ABS module along a pair of wires.

Wheel speed sensor DTCs automatically clear when a successful test drive is carried out. A successful test drive includes speeds above 32 km/h (20 mph) and at least one ABS stop.

This pinpoint test is intended to diagnose the following:
• Wiring, terminals or connectors
• Wheel speed sensor
• ABS module

PINPOINT TEST D: DTCs C0031:13, C0031:17, C0031:23 (LF), C0034:13, C0034:17, C0034:23 (RF), C0037:13, C0037:17, C0037:23 (LR), C003A:13, C003A:17 AND C003A:23 (RR)

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

Pinpoint Test E: DTCs C0031:2F, C0031:62, C0034:2F, C0034:62, C0037:2F, C0037:62, C003A:2F, C003A:62 and C0078:61

Normal Operation

The wheel speed sensors are active sensors and generate a square wave signal that is sent to the ABS module. When the ignition is turned to the RUN position, the ABS module carries out a self-test to determine if the sensors are functional. Voltage and ground are supplied to the front wheel speed sensors from the ABS module along 2 circuits.

Wheel speed sensor DTCs are set in continuous memory and they automatically clear when a successful test drive is carried out. A successful test drive includes speeds above 32 km/h (20 mph) and at least one ABS stop.

This pinpoint test is intended to diagnose the following:
• Mismatched tire sizes
• Wheel speed sensor ring
• Wheel speed sensor
• ABS module

PINPOINT TEST E: DTCs C0031:2F, C0031:62, C0034:2F, C0034:62, C0037:2F, C0037:62, C003A:2F, C003A:62 AND C0078:61

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

Pinpoint Test F: DTCs C0040:72 and C0040:73

Normal Operation

The ABS module receives brake pedal input from the PCM over the High Speed Controller Area Network (HS-CAN). The ABS module compares this information against other inputs (wheel speed signals, vehicle speed signal, brake pressure transducer) to determine if the brake pedal input is valid.

• DTC C0040:72 (Brake Pedal Switch "A": Actuator Stuck Open) — sets in continuous memory if the ABS module cannot detect the brake pedal input or if the brake pedal input does not match information from other sensors (wheel speed signals, vehicle speed signal, brake pressure transducer).
• DTC C0040:73 (Brake Pedal Switch "A": Actuator Stuck Closed) — sets in continuous memory when the ABS module senses vehicle speed and low brake fluid pressure, while the brake pedal input is indicating that the vehicle brakes are applied.

This pinpoint test is intended to diagnose the following:
• Brake pedal position switch

PINPOINT TEST F: DTCs C0040:72 AND C0040:73

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

Pinpoint Test G: DTC C1A98:54

Refer to Wiring Diagrams Cell 42 , Vehicle Dynamic Systems for schematic and connector information.

Normal Operation

The ABS module needs to be calibrated whenever a component specific to the Electronic Stability Control (ESC) system is disconnected or a new component is installed. Calibration allows the ABS module to identify the zero position of the sensors so the system can operate correctly.

• DTC C1A98:54 (Yaw Rate Sensor: Missing Calibration) — sets in continuous memory if the initialization sequence does not finish or if the ABS module loses the stability sensor calibration information.

This pinpoint test is intended to diagnose the following:
• ABS module calibration

PINPOINT TEST G: DTC C1A98:54

NOTE: The stability/traction control indicator (sliding car icon) flashes when a system calibration is required. Calibration is required after the ABS module or the Restraints Control Module (RCM) is replaced.

NOTE: The vehicle must be on level ground, at a complete standstill, in NEUTRAL with the brakes applied, and not on a hoist while carrying out the calibration procedure. Any vehicle movement results in calibration failure.

Pinpoint Test H: DTCs C1A99:14, C1A99:17, C1A99:2F, C1A99:62, C1A99:65 and C1A99:67

Normal Operation

The ABS module uses internal pressure sensors to determine correct operation by monitoring internal Hydraulic Control Unit (HCU) hydraulic pressures. These DTCs set if the brake pressure sensor signals do not match. This fault could set by either an internal ABS module failure or an HCU pressure sensor failure. The pressure sensors are internal to the HCU and cannot be serviced separately.

This pinpoint test is intended to diagnose the following:
• Stoplamp switch
• Brake pedal assembly
• ABS module
• HCU

PINPOINT TEST H: DTCs C1A99:14, C1A99:17, C1A99:2F, C1A99:62, C1A99:65 AND C1A99:67

Pinpoint Test I: DTC U0100:00

Refer to Wiring Diagrams Cell 42 , Vehicle Dynamic Systems for schematic and connector information.

Normal Operation
• DTC U0100:00 (Lost Communication With ECM/PCM "A": No Sub Type Information) — sets in continuous memory if the brake pedal position switch and traction control messages that should be received from the ECM/PCM, are missing for 5 seconds or longer.

This pinpoint test is intended to diagnose the following:
• Wiring, terminals or connectors
• PCM
• ABS module

PINPOINT TEST I: DTC U0100:00

Pinpoint Test J: DTC U0131:00

Normal Operation
• DTC U0131:00 (Lost Communication With Power Steering Control Module: No Sub Type Information) — sets in continuous memory and on-demand if the steering sensor message that should be received from the Power Steering Control Module (PSCM) is missing for 5 seconds or longer.

This pinpoint test is intended to diagnose the following:
• PSCM
• ABS module

PINPOINT TEST J: DTC U0131:00

Pinpoint Test K: DTC U0151:00

Refer to Wiring Diagrams Cell 42 , Vehicle Dynamic Systems for schematic and connector information.

Normal Operation
• DTC U0151:00 (Lost Communication With Restraints Control Module: No Sub Type Information) — sets in continuous memory and on-demand if the yaw rate or lateral accelerometer messages from the Restraints Control Module (RCM) are not received for 5 seconds or longer.

This pinpoint test is intended to diagnose the following:
• RCM
• ABS module

PINPOINT TEST K: DTC U0151:00

Pinpoint Test L: DTC U0155:00

Refer to Wiring Diagrams Cell 42 , Vehicle Dynamic Systems for schematic and connector information.

Normal Operation
• DTC U0155:00 (Lost Communication With Instrument Panel Cluster (IPC) Control Module: No Sub Type Information) — sets in continuous memory and on-demand if the traction control switch information or other sensor messages from the IPC are not received for 5 seconds or longer.

This pinpoint test is intended to diagnose the following:
• IPC
• ABS module

PINPOINT TEST L: DTC U0155:00

Pinpoint Test M: DTCs U1A00:49 and U1A00:87

Normal Operation

The Restraints Control Module (RCM) measures vehicle yaw rate and lateral acceleration and sends the information to the ABS module along a dedicated Controller Area Network (CAN). This dedicated CAN is used only for communication between the RCM and the ABS module. The yaw rate sensor lateral accelerometer are contained in the RCM .

• DTC U1A00:49 (Private Communication Network: Internal Electronic Failure) — sets in continuous memory when there is a communication issue between the ABS module and the RCM .
• DTC U1A00:87 (Private Communication Network: Missing Message ) — sets in continuous memory when expected messages such as yaw rate sensor and lateral accelerometer are missing for more than 5 seconds.

This pinpoint test is intended to diagnose the following:
• Wiring, terminals, or connectors
• RCM
• ABS module

PINPOINT TEST M: DTC U1A00:49 AND U1A00:87

 WARNING: Never probe the electrical connectors on airbag, Safety Canopy or side air curtain assemblies. Failure to follow this instruction may result in the accidental deployment of these assemblies, which increases the risk of serious personal injury or death.

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

Pinpoint Test N: DTC U3002:62

Refer to Wiring Diagrams Cell 42 , Vehicle Dynamic Systems for schematic and connector information.

Normal Operation

When the ignition is turned to the RUN position, the ABS module and the PCM share Vehicle Identification Number (VIN) information over the High Speed Controller Area Network (HS-CAN).

• DTC U3002:62 (Vehicle Identification Number: Signal Compare Failure) — sets in continuous memory and indicates that the VIN message sent by the PCM over the HS-CAN does not match the VIN stored in the ABS module.

This pinpoint test is intended to diagnose the following:
• Module configuration (ABS module and PCM)
• ABS module

PINPOINT TEST N: DTC U3002:62

Pinpoint Test O: THE TRACTION CONTROL SYSTEM CANNOT BE DISABLED

Refer to Wiring Diagrams Cell 42 , Vehicle Dynamic Systems for schematic and connector information.

Normal Operation

The traction control switch (part of the hazard flasher lamp switch) can be used by the driver to disable and enable the traction control systems. When the ignition is turned to the RUN position the stability/traction control OFF indicator (sliding car OFF icon) in the Instrument Panel Cluster (IPC) illuminates momentarily as a test. Momentarily pressing the switch disables the traction control system. When the traction control system is disabled through the use of the switch, the sliding car OFF icon illuminates continuously. The conventional ABS system cannot be disabled through the use of the stability/traction control switch. If a MyKey® restricted key is in use with the AdvanceTrac® always-on feature configured to on, the traction control system cannot be disabled. Only an admin key can be used to change a MyKey® traction control system setting from always-on to user select.

• DTC C0089:73 (TCS Disable Switch: Actuator Stuck Closed) — sets in continuous memory and on-demand if the stability/traction control switch is pressed for more than 30 seconds or the switch actuator is stuck.

This pinpoint test is intended to diagnose the following:
• Wiring, terminals or connectors
• Stability/traction control switch
• ABS module

PINPOINT TEST O: TRACTION CONTROL SYSTEM CANNOT BE DISABLED

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.