Control Module Communication Bus OFF- Electronically Controlled Brake System

BRAKE CONTROL: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: U0073/94,U0123/62,U0124/95,U0126/63,U0131/67,U0293/59: Control Module Communication Bus OFF
U0293/59 - Communication Error from HV ECU

DESCRIPTION

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

ABS / VSC / TRAC:

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 ECU CONNECTOR IS SECURELY CONNECTED

(a) Turn the power switch off.

(b) Check if each sensor and ECU connector is securely connected.

OK:

The connector should be securely connected.

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

3. RECONFIRM DTC

(a) Turn the power switch off.

(b) Record the output DTCs (for ABS, VSC, Electronically Controlled Brake, 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, VSC and Electronically Controlled Brake) after the CAN communication system returns to normal.

Result:





C -- CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION)

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

A -- INSPECT CAN COMMUNICATION SYSTEM

4. REPAIR OR REPLACE HARNESS OR CONNECTOR

(a) Turn the power 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 ECU Check For Intermittent Problems.

(d) Check that there is no momentary interruption.

NEXT -- Continue to next step.

5. RECONFIRM DTC

(a) Turn the power switch off.

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

(c) Turn the power switch on (READY).

(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, VSC and Electronically Controlled Brake DTCs are output, record them.

Result:





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

C -- END

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

A -- INSPECT CAN COMMUNICATION SYSTEM