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 if the AWC diagnostic trouble code No. U1003 is set. (Refer to DIAGNOSTIC TROUBLE CODE CHART .)

Q: Is the DTC set?
1. YES: Perform the relevant troubleshooting.
2. NO: Go to Step 3.
STEP 3. Scan tool diagnostic trouble code
Check if the AWC diagnostic trouble code No. C123C, C1242, C2114, C2115, or C2204 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 service data
Check the service data below. (Refer to DATA LIST REFERENCE TABLE .)
- Item No. 26: Yaw rate sensor
- Item No. 29: Lateral G sensor
- Item No. 31: Longitudinal G sensor
  Q: Is the check result normal?
  1. YES: Go to Step 5.
  2. NO: Replace the G and yaw rate sensor. (Refer to G AND YAW RATE SENSOR .) Then go to Step 6.
STEP 5. Check whether the DTC is reset.
Q: Is DTC No. U0428 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. U0428 set?
1. YES: Return to Step 1.
2. NO: This diagnosis is complete.