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.
^ 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.

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

Required Special Tools:
^ MB991958: Scan Tool (M.U.T.-III Sub Assembly)
^ MB991824: Vehicle Communication Interface (V.C.I.)
^ MB991827: M.U.T.-III USB Cable
^ MB991910: M.U.T.-III Main Harness

STEP 1. M.U.T.-III CAN bus diagnostics
Use scan tool to diagnose the CAN bus lines.
Q: Is the check result normal?
YES: Replace the steering wheel sensor. Then go to Step 2.
NO: Repair the CAN bus lines. On completion, go to Step 3.

STEP 2. Check whether the diagnostic trouble code is reset.
Q: Is DTC U0428 set?
YES: Replace the ASC-ECU.
NO: The procedure is complete.

STEP 3. Check whether the diagnostic trouble code is reset.
Q: Is DTC U0428 set?
YES: Return to Step 1.
NO: The procedure is complete.