Diagnostic Procedure

STEP 1. Scan tool CAN bus diagnostics
Using scan tool MB991958, diagnose the CAN bus lines.

Q: Is the check result normal?
1. YES: Go to Step 2.
2. NO: Repair the CAN bus lines. (Refer to TROUBLESHOOTING .)
STEP 2. Scan tool diagnostic trouble code
Check the ETACS diagnostic trouble code. (Refer to TROUBLESHOOTING .)

Q: Is the DTC set?
1. YES: Perform the relevant troubleshooting.
2. NO: Go to Step 3.
STEP 3. ETACS-ECU coding data check
Using the scan tool, check if there is any abnormality to the coding data stored in the ETACS-ECU. (Refer to CODING REFERENCE TABLE .)

Q: Is the check result normal?
1. YES: Go to Step 4.
2. NO: Replace the ETACS-ECU. (Refer to ETACS-ECU .) Then go to Step 5.
STEP 4. Check whether the DTC is reset.
Q: Is DTC No. U1415 set?
1. YES: Replace the AWC-ECU. (Refer to AWC-ECU .) Then go to Step 5.
2. NO: Intermittent malfunction. (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION .)
STEP 5. Check whether the DTC is reset.
Q: Is DTC No. U1415 set?
1. YES: Return to Step 1.
2. NO: This diagnosis is complete.