Inspection Procedure 4: No Diagnosis Code is Set even when the 4WD/LOCK Indicator Lamps Flash.
COMMENTS ON TROUBLE SYMPTOM
In case that the 4WD/LOCK indicator flashes but no diagnosis code is set, the 4WD-ECU power supply circuit system may have a problem.
If the 4WD-ECU power supply voltage is approximately 6.5 V or less when the system is in operation (always), the CPU of 4WD-ECU automatically shuts down. At this time, if the 4WD control is in operation, it switches to the 2WD control. 4WD-ECU cannot set the diagnosis code because the CPU shuts down. In addition, the combination meter determines the 4WD-ECU time-out, and flashes both 4WD and LOCK indicators.
PROBABLE CAUSES
Damaged wiring harness and connectors
4WD-ECU malfunction
DIAGNOSIS PROCEDURE
Inspection Procedure 1: M.U.T.-III cannot Communicate with the Electronic Control 4WD System. Refer to <ECU power supply circuit system check> .
.