Diagnostic Procedure

WARNING: This page is about a different variant/trim than selected.

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 line (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. C1078 set?
1. YES: Go to Step 3.
2. NO: This diagnosis is complete.
STEP 3. Check the tires
Check that the wheels/tires with the identical size are installed, and that each tire pressure is within the value specified on the tire pressure label.

Q: Is the check result normal?
1. YES: Go to Step 4.
2. NO: Install the wheels/tires with the identical size, or adjust the tire pressure. Then go to Step 5.
STEP 4. Scan tool diagnostic trouble code
Check the ASC diagnostic trouble code. (Refer to DIAGNOSTIC TROUBLE CODE TABLE ).

Q: Is the DTC set?
1. YES: Perform the relevant troubleshooting.
2. NO: Go to Step 5.
STEP 5. Scan tool data list
Check the following data list. (Refer to DATA LIST REFERENCE TABLE ).
- Item No. 22: Wheel speed sensor < FL >
- Item No. 23: Wheel speed sensor < FR >
- Item No. 24: Wheel speed sensor < RL >
- Item No. 25: Wheel speed sensor < RR >
Q: Is the check result normal?
1. YES: Intermittent malfunction. (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
2. NO: Replace the AWC-ECU. (Refer to AWC-ECU ).