Many malfunctions in the electrical system are caused by poor harness and terminals. 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 go to "Verification of Vehicle Repair" procedure
	▶ Go to "CAN communication circuit inspection" procedure.

Ignition "OFF"

Disconnect 4WD ECM connector and ABS ECM connector

Measure the resistance between CAN-HIGH terminal of 4WD ECM harness connector and CAN-HIGH terminal of ABS ECM harness connector.

Measure the resistance between CAN-LOW terminal of 4WD ECM harness connector and CAN-LOW terminal of ABS ECM harness connector.

Is the measured resistance within specification ?

	▶ Substitute with a known - good ECM and check for proper operation. If the problem is corrected, replace ECM and go to "Verification of Vehicle Repair" procedure.
	▶ Check for open/short in harness. ▶ Repair as necessary and then go to "Verification of Vehicle Repair" procedure.