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 3.
2. NO: Repair the CAN bus lines. (Refer to TROUBLESHOOTING .) After repairing the CAN bus line, go to Step 2.
STEP 2. Check whether the DTC is reset.
Q: Is DTC No. C1617 set?
1. YES: Go to Step 3.
2. NO: This diagnosis is complete.
STEP 3. Scan tool diagnostic trouble code
Check if the AWC-related DTC No. U0100, U0101, U0121, U0126, or U0141 is set. (Refer to DIAGNOSTIC TROUBLE CODE CHART .)

Q: Is the DTC set?
1. YES: Perform the relevant troubleshooting.
2. NO: Go to Step 4.
STEP 4. Scan tool diagnostic trouble code
- Check the engine diagnostic trouble code. (Refer to TROUBLESHOOTING .)
- Check the ASC diagnostic trouble code. (Refer to TROUBLESHOOTING .)
- 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 5.
STEP 5. Check whether the DTC is reset.
Q: Is DTC No. C1617 set?
1. YES: Replace the AWC-ECU. (Refer to AWC-ECU .) Then go to Step 6.
2. NO: Intermittent malfunction. (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION .)
STEP 6. Check whether the DTC is reset.
Q: Is DTC No. C1613 set?
1. YES: Return to Step 1.
2. NO: This diagnosis is complete.