ASC

DTC U0100 Engine time-out error

DTC U0101 CVT or TC-SST time-out error

DTC U0126 Steering wheel sensor time-out error

DTC U0141 ETACS time-out error

DTC U0136 AWC time-out error

CAUTION
^ If there is any problem in the CAN bus lines, an incorrect DTC may be set. Prior to this diagnosis, diagnose the CAN bus lines.
^ If DTCs U0100, U0101, U0126, U0141, and U0136 are set in ASC-ECU, always diagnose the CAN bus line. If there is any fault in the CAN bus lines, an incorrect DTC may be set. In this case, the set DTC is not highly reliable.
^ Before replacing the ECU, ensure that the communication circuit is normal.
^ When the steering wheel sensor is replaced, always carry out calibration to make ASC-ECU learn the neutral point.
^ 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.

DTC SET CONDITIONS
This DTC is set if ASC-ECU cannot receive the signal sent from other ECU for a certain period.

OPERATION
ASC-ECU communicates with the engine control module (ECM), CVT or TC-SST-ECU the steering wheel sensor, ETACS-ECU and AWC-ECU via the CAN bus lines.

PROBABLE CAUSES

DTC U0100
^ Wiring harness or connector failure of CAN bus line
^ Engine control module (ECM) malfunction
^ ASC-ECU malfunction

DTC U0101
^ Wiring harness or connector failure of CAN bus line
^ CVT or TC-SST-ECU malfunction
^ ASC-ECU malfunction

DTC U0126
^ Wiring harness or connector failure of CAN bus line
^ Steering wheel sensor malfunction
^ ASC-ECU malfunction

DTC U0141
^ Wiring harness or connector failure of CAN bus line
^ Malfunction of ETACS-ECU
^ ASC-ECU malfunction

DTC U0136
^ Wiring harness or connector failure of CAN bus line
^ Malfunction of TC-SST-ECU
^ 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 diagnosis
Use scan tool to diagnose the CAN bus lines.

Q: Is the check result normal?
YES: Go to Step 2.
NO: Repair the CAN bus lines. On completion, go to Step 4.

STEP 2. Check whether the DTC is reset.

Q: Is DTC U0100, U0101, U0126, U0141 or U0136 set?
YES: Go to Step 3.
NO: The procedure is complete.

STEP 3. M.U.T.-III other system DTC
Use scan tool to check that other DTC is set in the ECU corresponding to the relevant diagnosis.

Q: Is other DTC set?
YES: Troubleshoot for the relevant DTC.
NO: Go to Step 4.

STEP 4. M.U.T.-III DTC
Use scan tool to check if the same DTC (time-out) is set in the other ECU (CAN-C).

Q: Is any DTC set?
YES (DTC U0100 is set): Replace the engine control module (ECM), and then go to Step 5.
YES (DTC U0101 is set): Replace the CVT or TC-SST-ECU, and then go to Step 5.
YES (DTC U0126 is set): Replace steering wheel sensor, and then go to Step 5.
YES (DTC U0141 is set): Replace the ETACS-ECU, and then go to Step 5.
YES (DTC U0136 is set): Replace the AWC-ECU, and then go to Step 5.
NO (No DTC is set.): The procedure is complete.

STEP 5. Check whether the DTC is reset.

Q: Is DTC U0100, U0101, U0126, U0141 or U0136 set?
YES: Replace the hydraulic unit (ASC-ECU).
NO: The procedure is complete.