Possible Causes
- Wheels or tires
- Wiring, terminals or connectors
- RCM
- ABS module
CONNECTOR PIN REFERENCE (HARNESS SIDE)
| Circuit | Pin |
|---|---|
| CAN- (Controller Area Network) - VCA24 | 20 (GREEN/ORANGE) |
| CAN+ (Controller Area Network) - VCA23 | 33 (BLUE/WHITE) |
CONNECTOR PIN REFERENCE (HARNESS SIDE)
| Circuit | Pin |
|---|---|
| CAN- (Controller Area Network) - VCA24 | 59 (GREEN/ORANGE) |
| CAN+ (Controller Area Network) - VCA23 | 60 (BLUE/WHITE) |
CONNECTOR PIN REFERENCE (HARNESS SIDE)
| Circuit | Pin |
Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may cause damage to the connector.
- G1: CHECK THE WHEELS AND TIRES
- Inspect the wheels and tires for any damage or excessive wear.
- Verify all wheels and tires are the same size and match the size indicated on the VC label.
- Verify the inflation pressure of all 4 tires is correct as indicated on the VC label.
- Are the wheels and tires OK?
Yes No Go to G2. INSTALL the correct size wheel or tire or ADJUST tire pressure as necessary.
- G2: CHECK THE COMMUNICATION NETWORK
- Ignition ON, engine OFF.
- Press the Read Vehicle Information button to view the results of the modules communicating on the network
- Retrieve the continuous memory DTCs.
- Does the RCM pass the Network Test?
Yes No Go to G3. REFER to MODULE COMMUNICATIONS NETWORK to diagnose the RCM does not communicate with the scan tool.
- G3: CHECK THE ABS MODULE DTCS
- G4: RETRIEVE ALL DTCS FROM THE RCM
- Carry out the RCM self-test.
- Are any DTCs present?
Yes No DIAGNOSE the RCM DTCs first. REFER to SUPPLEMENTAL RESTRAINT SYSTEM . Go to G5.
- G5: VERIFY STABILITY CONTROL SENSOR CALIBRATION NOTE: The vehicle must be on level ground and at a complete standstill during IMU Calibration. Any vehicle movement results in a failed calibration.
- Using a diagnostic scan tool, carry out the IMU Calibration routine. Follow the diagnostic scan tool directions.
- Ignition OFF.
- Ignition ON, engine OFF.
- Test drive the vehicle above 12 km/h (7 mph) and at least once make a left turn and a right turn.
- Carry out the ABS self-test.
- Is one or more DTC shown in the ABS Module DTC Fault Trigger Conditions table present?
Yes No Go to G6. The condition that caused the concern is no longer present. The concern was most likely due to an incomplete calibration or a failed calibration of the stability control sensors.
- G6: CHECK THE ABS MODULE STABILITY CONTROL SENSOR PID VALUES NOTE: The vehicle must be on level ground and at a complete standstill during PID monitoring. Any vehicle movement results in false values for this test.
- Ignition OFF.
- Ignition ON, engine OFF.
- Access the ABS and monitor the YAW_RATE (ANGV) PID.
- Access the ABS and monitor the ROLL_RATE (ANGV) PID.
- Access the ABS and monitor the LAT_ACCL (ACC) PID.
- Access the ABS and monitor the LONG_ACCL (ACC) PID.
- Are the YAW_RATE and ROLL_RATE PID values between -0.05 and 0.05, and are the LAT_ACCL and LONG_ACCL PID values between -0.04 and 0.04?
Yes No Go to G11. For Transit, Go to G7.
For all others, Go to G11.
- G7: CHECK THE PRIVATE HS-CAN CIRCUITS FOR A SHORT TO VOLTAGE WARNING: Turn the ignition OFF and wait one minute to deplete the backup power supply. Failure to follow this instruction may result in serious personal injury or death in the event of an accidental deployment.
- Ignition OFF.
- Wait one minute.
- RCM_A connector disconnected. (C310A)
- RCM_B connector disconnected. (C310B)
- ABS Module connector disconnected. (C135)
- Ignition ON, engine OFF.
- Measure the voltage between:
(+) (-) ABS Module (C135) Connector, Harness Side CAN- - VCA24 (GREEN/ORANGE) - Pin 20 Ground CAN+ - VCA23 (BLUE/WHITE) - Pin 33 Ground - Is any voltage present?
Yes No REPAIR the circuit in question. Go to G8.
- G8: CHECK THE PRIVATE HS-CAN CIRCUITS FOR A SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between:
(+) (-) ABS Module (C135) Connector, Harness Side CAN- - VCA24 (GREEN/ORANGE) - Pin 20 Ground CAN+ - VCA23 (BLUE/WHITE) - Pin 33 Ground - Are the resistances greater than 10, 000 ohms?
Yes No Go to G9. REPAIR the circuit in question.
- G9: CHECK THE PRIVATE HS-CAN CIRCUITS FOR A SHORT TOGETHER
- Measure the resistance between:
(+) (-) ABS Module (C135) Connector, Harness Side ABS Module (C135) Connector, Harness Side CAN- - VCA24 (GREEN/ORANGE) - Pin 20 CAN+ - VCA23 - Pin 33 - Is the resistance greater than 10, 000 ohms?
Yes No Go to G10. REPAIR the circuits.
- Measure the resistance between:
- G10: CHECK THE PRIVATE HS-CAN CIRCUITS FOR AN OPEN
- Measure the resistance between:
(+) (-) ABS Module (C135) Connector, Harness Side RCM_B (C310B) Connector, Harness Side CAN- - VCA24 (GREEN/ORANGE) - Pin 20 CAN- - VCA24 - Pin 59 CAN+ - VCA23 (BLUE/WHITE) - Pin 33 CAN+ - VCA23 - Pin 60 - Are the resistances less than 3 ohms?
Yes No Go to G11. REPAIR the circuit in question.
- Measure the resistance between:
- G11: CHECK THE RCM INSTALLATION AND MOUNTING SURFACE WARNING: Turn the ignition OFF and wait one minute to deplete the backup power supply. Failure to follow this instruction may result in serious personal injury or death in the event of an accidental deployment.
- Ignition OFF.
- Wait one minute.
- RCM_A connector disconnected. (C310A) (if not previously disconnected)
- RCM_B connector disconnected. (C310B) (if not previously disconnected)
- Inspect the RCM installation, make sure the fasteners are fully seated and tightened to specifications. Refer to SUPPLEMENTAL RESTRAINT SYSTEM .
- Inspect the RCM mounting surface for damage, corrosion or dirt.
- the RCM installed correctly and is the mounting surface clean and free from damage?
Yes No Go to G12. CLEAN or REPAIR the mounting surface or INSTALL a new RCM as necessary. REFER to SUPPLEMENTAL RESTRAINT SYSTEM .
- G12: VERIFY ALL WIRING CONNECTIONS WARNING: Turn the ignition OFF and wait one minute to deplete the backup power supply. Failure to follow this instruction may result in serious personal injury or death in the event of an accidental deployment.
- Ignition OFF.
- Wait one minute.
- RCM_A connector disconnected. (C310A) (if not previously disconnected)
- RCM_B connector disconnected. (C310B) (if not previously disconnected)
- ABS Module connector disconnected. (C135)
- Disconnect all in-line electrical connectors between the ABS module and the RCM.
- Using a good light source, inspect all disconnected electrical connectors for the following:
- corrosion - install new connector or terminal and clean the module pins
- damaged or bent pins - install new terminals or pins
- pushed-out pins - install new pins as necessary
- spread terminals - install new terminals as necessary
- Are the connectors free of corrosion, damaged pins, bent pins, pushed-out pins and spread terminals?
Yes No Go to G13. REPAIR the affected connectors or terminals. REFER to OEM CONNECTOR REPAIR PROCEDURES for schematic and connector information.
- G13: CHECK THE RCM FOR CORRECT OPERATION
- ABS Module connector connected. (C135)
- RCM_A connector connected. (C310A)
- RCM_B connector connected. (C310B)
- Connect all in-line electrical connectors between the ABS module and the RCM.
- Operate the system and determine if the concern is still present.
- Is the concern still present?
Yes No CHECK OASIS for any applicable Technical Service Bulletins TSBs. If a TSB exists for this concern, DISCONTINUE this test and FOLLOW the TSB instructions.
If no TSBs address this concern, DIAGNOSE the RCM concern. REFER to SUPPLEMENTAL RESTRAINT SYSTEM .The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. ADDRESS the root cause of any connector or pin issues.