Diagnostic Procedure
- STEP 1. Scan tool CAN bus diagnostics
Using scan tool MB991958, diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Go to Step 3.
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. C1613 set?
YES : Go to Step 3.
NO : This diagnosis is complete.
- STEP 3. Intermediate connector, AWC-ECU connector, AWC switch connector check: C-42, C-46, C-120
Q: Is the check result normal?
YES : Go to Step 4.
NO : Repair the defective connector. Then go to Step 8.
- STEP 4. Wiring harness check between C-46 AWC-ECU connector terminal No. 21 and C-120 AWC switch connector terminal No. 1
Check the wiring harness for short circuit (short to power supply).
Q: Is the check result normal?
YES : Go to Step 5.
NO : Repair the wiring harness. Then go to Step 8.
- STEP 5. Scan tool service data
Item No. 89: AWC switch (Refer to SERVICE DATA REFERENCE TABLE .)
Q: Is the check result normal?
YES : Go to Step 7.
NO : Go to Step 6.
- STEP 6. AWC switch single unit check
Check the AWC switch.(Refer to AWC SWITCH CHECK .)
Q: Is the check result normal?
YES : Go to Step 7.
NO : Replace the AWC switch.(Refer to AWC-ECU .) Then go to Step 8.
- STEP 7. Check whether the DTC is reset.
Q: Is DTC No. C1613 set?
YES : Replace the AWC-ECU.(Refer to AWC-ECU .) Then go to Step 8.
NO : Intermittent malfunction. (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION .)
- STEP 8. Check whether the DTC is reset.
Q: Is DTC No. C1613 set?
YES : Return to Step 1.
NO : This diagnosis is complete.