Diagnosis flow code: F

Step	Action	Yes	No
1	Power and ground circuit check of 4WD control module Check 4WD control module power and ground circuits. Is it in good condition?	Go to Step 2.	Repair power and/or ground circuit.
2	CAN communication circuit check Turn ignition switch to OFF position. Disconnect connector from 4WD control module and ABS/ESP® control module. Check for proper terminal connection to CAN communication circuit at 4WD control module and ABS/ESP® control module connectors. If OK, check CAN communication circuits between 4WD control module connector and ABS/ESP® control module connector for breaking. Is each CAN communication circuit in good condition?	Substitute a known-good 4WD control module and recheck.	Repair CAN communication circuit.