U0428

DTC U0428: Communication error in steering wheel sensor

CAUTION:

- If there is any problem in the CAN bus lines, an incorrect diagnostic trouble code may be set. Prior to this diagnosis, diagnose the CAN bus lines CAN Bus Line Diagnostics Flow ).
- If diagnostic trouble code U0428 is set in ASC-ECU, always diagnose the CAN bus line. If there is any fault in the CAN bus lines, an incorrect diagnostic trouble code may be set. In this case, the set diagnostic trouble code is not highly reliable.
- Before replacing the ECU, ensure that the communication circuit is normal.
- When the hydraulic unit (integrated with ASC-ECU) is replaced, always carry out the calibration of the steering wheel sensor, the G and yaw rate sensor and brake fluid pressure sensor (Refer to Testing and Inspection , Testing and Inspection and Testing and Inspection ).

CIRCUIT OPERATION

The steering wheel sensor outputs the steering wheel status to ASC-ECU via the CAN bus lines.

DTC SET CONDITIONS

This diagnostic trouble code is set when ASC-ECU has detected the communication error in the steering wheel sensor.

PROBABLE CAUSES

- Steering wheel sensor malfunction
- ASC-ECU malfunction
- External noise interference

DIAGNOSIS

STEP 1. Using scan tool MB991958, diagnose the CAN bus lines.

Use scan tool to diagnose the CAN bus lines.

Q. Is the check result normal?

YES Replace the steering wheel sensor (Refer to Service and Repair). Then go to Step 2.
NO Repair the CAN bus lines CAN Bus Diagnostics Chart).
On completion, go to Step 3.
STEP 2. Check whether the DTC is reset.

Erase the DTC.

Q. Is DTC U0428 set?

YES Replace the hydraulic unit (integrated with ASC-ECU) (Refer to Service and Repair).
NO The procedure is complete.
STEP 3. Check whether the DTC is reset.

Erase the DTC.

Q. Is DTC U0428 set?

YES Return to Step 1.
NO The procedure is complete.