Control Module Communication Bus OFF

BRAKE CONTROL: VEHICLE STABILITY CONTROL SYSTEM: U0073/94,U0100/65,U0123/62,U0124/95,U0126/63: Control Module Communication Bus OFF
U0126/63 - Lost Communication with Steering Angle Sensor Module

DESCRIPTION

The skid control ECU receives the signals from the ECM, 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 Techstream, check for any momentary interruption in the wire harness and connector corresponding to a DTC Check For Intermittent Problems.

ABS / VSC / TRAC:





Result:





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

C -- REPAIR OR REPLACE HARNESS OR CONNECTOR

B -- RECONFIRM DTC
A -- Continue to next step.

2. CHECK IF EACH SENSOR AND ECM CONNECTOR IS SECURELY CONNECTED

(a) Turn the engine switch off.

(b) Check if each sensor or ECM connector is securely connected.

OK:

The connector is securely connected.

NG -- CONNECT CONNECTOR TO EACH SENSOR OR ECM CORRECTLY
OK -- Continue to next step.

3. RECONFIRM DTC

(a) Turn the engine switch off.

(b) Record the output DTCs (for ABS, VSC, and CAN communication).

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

Result:





C -- CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION)

B -- REPAIR CIRCUIT INDICATED BY OUTPUT DTC Vehicle Stability Control System

A -- INSPECT CAN COMMUNICATION SYSTEM

4. REPAIR OR REPLACE HARNESS OR CONNECTOR

(a) Turn the engine switch off.

(b) Repair or replace the harness or connector.

(c) Check for any momentary interruption between the skid control ECU and each sensor or ECM Check For Intermittent Problems.

(d) Check that there is no momentary interruption.

NEXT -- Continue to next step.

5. RECONFIRM DTC

(a) Turn the engine switch off.

(b) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

(c) Start the engine.

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

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

(f) If ABS and VSC DTCs are output, record them.

Result:





HINT
The CAN communication system must be normal when repairing each sensor DTC (for ABS and VSC).

C -- END

B -- REPAIR CIRCUIT INDICATED BY OUTPUT DTC Vehicle Stability Control System

A -- INSPECT CAN COMMUNICATION SYSTEM