Hands-Free Cellular Phone System
DTC U0154: OCM CAN TimeoutCAUTION:
- If DTC U0154 is set, be sure to diagnose the CAN bus line.
- When replacing the ECU, always check that the communication circuit is normal.
DIAGNOSTIC FUNCTION
When the signals from occupant classification-ECU cannot be received, the hands free module sets DTC U0154.
TROUBLESHOOTING HINTS
- The CAN bus line may be defective.
- The hands free module may be defective.
- The occupant classification-ECU may be defective.
DIAGNOSIS
Required Special Tools:
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicles 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 occupant classification-ECU diagnostic trouble code.
Check if DTC is set to the occupant classification-ECU.
Q : Is the DTC set?
YES : Troubleshoot the SRS (Refer to SRS, Diagnosis).
NO : Go to Step 3.
STEP 3. Recheck for diagnostic trouble code.
Check again if the DTC is set to the hands free module.
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 hands free module.
NO : The trouble can be an intermittent malfunction (Refer to General (Body and Chassis), How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction).