STEP 1. Scan tool MB991958 CAN bus diagnostics
STEP 2. Retest the system.
STEP 3. Scan tool MB991958 actuator test.
STEP 4. Resistance measurement between the drive mode selector connector terminals
STEP 5. Wiring harness check
(1) Check the wiring harness between the C-228 AWD-ECU connector (terminals No.14 and 16) and the C-40 drive mode selector connector (terminal No.2).
(2) Check the connector(s) or terminal(s) or wiring harness above for damage or other problem.
Is the check result normal?
Go to Step 6 Repair the connector(s) or terminal(s) or wiring harness.
STEP 6. Resistance measurement at the drive mode selector connector
(1) Disconnect the drive mode selector connector.
(2) Measure the resistance between the drive mode selector wiring harness side connector and the body ground.OK: Continuity exists (2 Ω or less)
Is the check result normal?
Go to Step 7 Repair the connector(s) or terminal(s) or wiring harness.
STEP 7. Scan tool MB991958 data list.
STEP 8. Retest the system.
STEP 9. Retest the system.