Many malfunctions in the electrical system are caused by poor harness(es) and terminal condition.

Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.

Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.

Has a problem been found ?

	▶ Repair as necessary and then go to "Verification of Vehicle Repair" procedure.
	▶ Go to "Power circuit inspection" procedure.

Ignition "ON" & Engine "OFF".

Disconnect the 4WD ECM connector.

Measure voltage between power supply terminal of the 4WD ECM harness connector and chassis ground.

Is the measured value within specifications ?

	▶ Go to "Ground Circuit Inspection" procedure.
	▶ Repair open or short in power circuit between battery and 4WD ECM harness connector. Check for open or blown fuse referring to "Circuit Diagram".

Ignition "OFF".

Disconnect the 4WD ECM connector.

Measure resistance between ground terminal of the 4WD ECM harness connector and chassis ground.

Is the measured resistance within specifications ?

	▶ Go to "CAN Circuit Inspection" procedure.
	▶ Repair open between ground teminal of the 4WD ECM harness connector and chassis ground.

Ignition "OFF".

Disconnet the HECU harness connector and 4WD ECM harness connector.

Measure resistance between CAN HIGH(LOW) terminal of the HECU harness connector and CAN HIGH(LOW) terminal of the 4WD ECM harness connector.

Is the measured value within specifications ?

	▶ Go to "Component inspection" procedure.
	▶ Repair open in CAN BUS line between HECU harness connector and 4WD ECM harness connector and then go to "Verification of Vehicle Repair" procedure.