U1003

DTC U1003: G and yaw rate sensor bus-off

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.

CIRCUIT OPERATION
The G and yaw rate sensor outputs the signal to ASC-ECU via the special CAN bus lines.

DTC SET CONDITIONS
This diagnostic trouble code is set when ASC-ECU cannot receive the signal sent from the G and yaw rate sensor.

PROBABLE CAUSES
^ Wiring harness or connector failure for the special CAN bus lines between ASC-ECU and the G and yaw rate sensor
^ ASC-ECU malfunction

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 A

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: Go to Step 3.
NO: Repair the CAN bus lines. On completion, go to Step 2.

STEP 2. Diagnostic trouble code recheck after resetting CAN bus lines
Q: Is DTC U0125 set?
YES: Go to Step 3.
NO: The procedure is complete.

STEP 3. Connector check: A-08 ASC-ECU connector, C-20 G and yaw rate sensor connector
Q: Is the check result normal?
YES: Go to Step 4.
NO: Repair the connector, and then go to Step 5.

STEP 4. Wiring harness check between A-08 ASC-ECU connector terminals No. 29/25 and C-20 G and yaw rate sensor connector terminals No. 2/3
Check for open circuit in communication circuit
Q: Is the check result normal?
YES: Go to Step 5.
NO: Repair the wiring harness, and then go to Step 5.

STEP 5. Check whether the diagnostic trouble code is reset.
Q: Is DTC U0125 set?
YES: Replace the G and yaw rate sensor, and then go to Step 6.
NO: The procedure is complete.

STEP 6. Check whether the diagnostic trouble code is reset.
Q: Is DTC U0125 set?
YES: Replace the ASC-ECU.
NO: The procedure is complete.