Inspection Procedure 4

Inspection Procedure 4: No DTC is set even when the AWD/LOCK Indicator Lamps Flash.

COMMENTS ON TROUBLE SYMPTOM
^ In case that the AWD/LOCK indicator flashes but no DTC is set, the AWD-ECU power supply circuit system or 4WD-ECU may have a problem.
^ If the AWD-ECU power supply voltage is approximately 6.5 V or less when the system is in operation (always), the CPU of AWD-ECU automatically shuts down. At this time, if the AWD control is in operation, it switches to the FWD control. AWD-ECU cannot set the DTC because the CPU shuts down. In addition, the combination meter determines the AWD-ECU time-out, and flashes both AWD and LOCK indicators.

PROBABLE CAUSES
^ Damaged wiring harness and connectors
^ AWD-ECU malfunction

DIAGNOSIS
^ MB991958: Scan Tool (M.U.T.-III Sub Assembly)
^ MB991824: Vehicle Communication Interface
^ MB991827: M.U.T.-III USB Cable
^ MB991910: M.U.T.-III Main Harness A

Inspection Procedure 1: Scan tool MB991958 cannot communicate with the Electronic Control AWD System. Refer to ECU power supply circuit system check.