S-Awc-ECU CAN Timeout
DTC U0136: S-AWC-ECU CAN TimeoutCAUTION:
- If DTC U0136 is set to the ETACS-ECU, always diagnose the CAN bus line.
- Before replacing the ECU, ensure that the communication circuit is normal.
TROUBLE JUDGMENT
If the signal from S-AWC-ECU cannot be received, the ETACS-ECU sets DTC U0136.
JUDGMENT CRITERIA
After the following statuses continue to be true for 5 seconds, if the communication with the S-AWC-ECU cannot be established for 0.6 second or more, the ETACS-ECU determines that a problem has occurred.
- No abnormality is present to the network.
- Ignition switch is in the ON position.
- No abnormality is present to the power supply fuse, or the odometer value is at 80.5 km (50.0 miles) or more.
- ETACS-ECU system voltage is at 10 - 16 volts.
TROUBLESHOOTING HINTS
- The S-AWC-ECU may be defective.
- The ETACS-ECU may be defective.
- The CAN bus may be defective.
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 (Vehicles with CAN communication system)
STEP 1. Using scan tool MB991958, diagnose the CAN bus line.
CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
1. Connect scan tool MB991958. Refer to "How to connect the Scan Tool (M.U.T.-III)." Scan Tool Connecting
2. Turn the ignition switch to the "ON" position.
3. Diagnose the CAN bus line.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q : Is the CAN bus line found to be normal?
YES : Go to Step 2.
NO : Repair the CAN bus line (Refer to Controller Area Network, Diagnosis).
STEP 2. Using scan tool MB991958, read the S-AWC-ECU diagnostic trouble code.
Check if DTC is set to the S-AWC-ECU.
Q : Is the DTC set?
YES : Troubleshoot the S-AWC (Refer to M/T, Diagnosis).
NO : Go to Step 3.
STEP 3. Using scan tool MB991958, read the ASC-ECU diagnostic trouble code.
Check if the DTC U0136 is set to the ASC-ECU.
Q : Is the DTC set?
YES : Go to Step 4.
NO : Go to Step 5.
STEP 4. Recheck for diagnostic trouble code.
Check again if the DTC is set to the ETACS-ECU.
1. Erase the DTC.
2. Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
3. Check if DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q : Is the DTC set?
YES : Replace the S-AWC-ECU.
NO : The trouble can be an intermittent malfunction such as a poor connection or open circuit in the CAN bus lines between the S-AWC-ECU and the ETACS-ECU (Refer to General (Body and Chassis), How to Cope with Intermittent Malfunction).
STEP 5. Recheck for diagnostic trouble code.
Check again if the DTC is set to the ETACS-ECU.
1. Erase the DTC.
2. Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
3. Check if DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q : Is the DTC set?
YES : Replace the ETACS-ECU.
NO : The trouble can be an intermittent malfunction such as a poor connection or open circuit in the CAN bus lines between the S-AWC-ECU and the ETACS-ECU (Refer to General (Body and Chassis), How to Cope with Intermittent Malfunction).