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 all connectors(and connections) for looseness, bending, corrosion, contamination, deterioration, and/or damage.

Has a problem been found ?

	▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure.
	▶ Go to "Power Circuit Inspection" procedure.

Ignition "OFF".

Disconnect HECU connector

Ignition "ON".

Measure voltage between power terminal of HECU and chassis ground.

Is measured value within specification?

	▶ Go to "Ground Circuit Inspection" procedure.
	▶ Repair open or short in power circuit between battery and HECU harness connector and then go to "Verification of vehicle Repair" procedure.

Ignition "OFF".

Disconnect Battery (-) terminal.

Disconnect HECU connector.

Measure resistance between ground terminal of HECU harness connector and chassis ground.

Is measure value within specification?

	▶ Go to "Component Inspection" procedure.
	▶ Repair open or short in ground circuit of HECU harness connector and then go to "Verification of vehicle Repair" procedure.