Electronic Control

DTC U0141: ETACS CAN time-out

CAUTION:
^ If there is any problem in the CAN bus lines, an incorrect DTC may be set. Prior to this diagnosis, always diagnose the CAN bus lines.
^ Before replacing the ECU, ensure that the communication circuit is normal.

OPERATION
AWD-ECU receives the data (such as drive mode display signal, failure information signal) from ETACS-ECU via the CAN bus lines. If it cannot receive such data, illuminates the AWD indicator.

DTC SET CONDITIONS
If the following conditions are met when the system is in operation (always), AWD-ECU flashes the AWD/LOCK indicators alternately, and sets the DTC No. U0141.

^ IG1 power supply voltage: 8 V or more
^ The signal output from ETACS-ECU cannot be received.

TROUBLESHOOTING HINTS

Current trouble
^ Wiring harness or connector failure in the CAN bus lines between ETACS-ECU and AWD-ECU
^ Malfunction of ETACS-ECU
^ AWD-ECU malfunction

Past trouble
^ Refer to "How to treat past trouble" for proceeding the diagnostics. Diagnose mainly wiring harness or connector failure in the CAN bus lines between ETACS-ECU and AWD-ECU, and malfunction in the power supply system for ETACS-ECU.

NOTE: For a past trouble, you cannot find it by the scan tool MB991958 CAN bus diagnostics even if there is any failure in CAN bus lines. In this case, check the CAN bus lines in the same manner as How to Cope with Intermittent Malfunction. You can narrow down the possible cause of the trouble by referring to the DTC, which is set regarding the CAN communication-linked ECUs.

DIAGNOSIS
^ MB991958: Scan Tool (M.U.T.-III Sub Assembly)
^ MB991824: Vehicle Communication Interface
^ MB991827: M.U.T.-III USB Cable
^ MB991910: M.U.T.-III Main Harness A

STEP 1. Scan tool MB991958 CAN bus diagnostics
Use scan tool MB991958 to diagnose the CAN bus lines.

Q:Is the check result normal?
YES: Go to Step 2.
NO: Repair the CAN bus line. Then go to Step 2.

STEP 2. Scan tool MB991958 data list
Check the following service data.

^ Item 09: CAN system (ETACS)

Q:Is the check result normal?
YES: Go to Step 6.
NO: Go to Step 3.

STEP 3. Scan tool M B991958 DTC of other systems
Check if a DTC, which relates to the CAN communication-linked systems below, is set.

^ Meter
U0141: ETACS CAN time-out DTC
^ A/C
U0141: ETACS CAN time-out DTC
^ Engine
U0141: ETACS CAN time-out DTC

Q:Is the DTC set?
YES: Go to Step 4.
NO: Go to Step 5.

STEP 4. Check whether the DTC is reset.
(1) Erase the DTC.
(2) Turn the ignition switch from the LOCK (OFF) position to the ON position.
(3) Check if the DTC is set.

Q:Is the DTC No. U0141 set?
YES: Replace ETACS-ECU. Then go to Step 6.
NO: A poor connection, open circuit or other intermittent malfunction in the CAN bus lines between ETACS-ECU and AWD-ECU is suspected.

STEP 5. Check whether the DTC is reset.
(1) Erase the DTC.
(2) Turn the ignition switch from the LOCK (OFF) position to the ON position.
(3) Check if the DTC is set.

Q:Is the DTC No. U0141 set?
YES: Replace AWD-ECU. Then go to Step 6.
NO: A poor connection, open circuit or other intermittent malfunction in the CAN bus lines between ETACS-ECU and AWD-ECU is suspected.

STEP 6. Check whether the DTC is reset.

Q:Is the DTC No. U0141 set?
YES: Diagnose again from Step 1.
NO: This diagnosis is complete.