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 "Alternator Output Voltage Inspection" procedure.

Ignition "ON" & Engine "ON".

Maintain ENG RPM 2,500RPM over 2 minutes.

Measure voltage between the battery terminal(+) and the battery terminal(-).

Is the measured value within specifications?

	▶ Go to "Power Circuit Inspection" procedure.
	▶ Check for damaged harness and poor connection between alternator and battery. If OK repair or replace alternator and then go to "Verification of vehicle Repair" procedure.

Ignition "ON" & Engine "OFF".

Measure voltage between the battery terminal(+) and power terminal of the HECU harness connector.

Is the measured value within specifications?

	▶ 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" & Engine "OFF".

Disconnect HECU connector.

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

Is the measured value within specifications?

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