Many malfunctions in the electrical system are caused by poor harness(es) 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 then go to "Verification of Vehicle Repair" procedure.
	▶ Go to "Signal Circuit Inspection" procedure.

Ignition "OFF" & Engine "OFF".

Disconnect HECU and PCM connector.

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

Is the measured resistance within specifications?

	▶ Go to "Component Inspection" procedure.
	▶ Repair open in CAN BUS line between HECU harness connector and PCM harness connector and then go to "Verification of Vehicle Repair" procedure.