Control Module Communication Bus OFF- Electronically Controlled Brake System

BRAKE CONTROL: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: U0073/94, U0100/65, U0123/62, U0124/95, U0126/63, U0130/68, U0131/67: Control Module Communication Bus OFF
U0131/67 - Lost Communication with Power Steering Control Module

DESCRIPTION

The skid control ECU inputs the signals from the ECM, power steering (EPS) ECU, steering control (VGRS) ECU, steering angle sensor, and yaw rate and acceleration sensor via the CAN communication system.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION)

(a) Using the Techstream, check for any momentary interruption in the wire harness and connector corresponding to a DTC Check For Intermittent Problems.

ABS / VSC / TRAC:





OK:

There are no momentary interruptions.

HINT
Perform the above inspection before removing the sensor and connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

2. RECONFIRM DTC

(a) Record the output DTCs (for ABS, VSC, Electronically Controlled Brake System and CAN communication) Electronically Controlled Brake System for ABS, VSC and Electronically Controlled Brake System, or Diagnosis System for CAN).

HINT
If the CAN communication system DTC and the relevant sensor DTCs are output simultaneously, troubleshoot the relevant sensor DTCs (for ABS, VSC and Electronically Controlled Brake System) after the CAN communication system returns to normal.

Result:





B -- REPAIR CIRCUIT INDICATED BY OUTPUT CODE

A -- REPAIR CAN COMMUNICATION SYSTEM How to Proceed With Troubleshooting

3. REPAIR OR REPLACE HARNESS OR CONNECTOR

(a) Repair or replace the harness or connector.

(b) Check for any momentary interruption between the skid control ECU and each sensor or ECM.

(c) Check that there is no momentary interruption.

NEXT -- Continue to next step.

4. RECONFIRM DTC

(a) Clear the DTC Electronically Controlled Brake System.

(b) Start the engine.

(c) Drive the vehicle and turn the steering wheel to the right and left at a speed of 15 km/h (9 mph) or more.

(d) Check that no CAN communication system DTC is output.

(e) If ABS, VSC and Electronically Controlled Brake System DTCs are output, record them.

Result:





HINT
The CAN communication system must be normal when repairing the sensor DTCs (for ABS, VSC and Electronically Controlled Brake System).

C -- END

B -- REPAIR CIRCUIT INDICATED BY OUTPUT CODE Electronically Controlled Brake System

A -- REPAIR CAN COMMUNICATION SYSTEM How to Proceed With Troubleshooting