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 "Ground Circuit Inspection" procedure.

Ignition "OFF".

Disconnect Battery (-) terminal.

Refer to "Shop Manual" and disconnect Knock Sensor connector.

Measure resistance between Pin No. 2 (Ground) terminal of Knock Sensor harness connector and chassis ground.

Is measured value within specification?

	▶ Go to "Signal Circuit Inspection" procedure.
	▶ Repair open or short in ground circuit between Knock Sensor and chassis ground and then go to "Verification of vehicle Repair" procedure.

Ignition "OFF".

Refer to "Shop Manual" and disconnect Knock Sensor connector.

Ignition "ON".

Measure voltage between Pin No. 1 (Signal) terminal of Knock Sensor harness connector and chassis ground.

Ignition "OFF".

Disconnect Battery (-) terminal.

Refer to "Shop Manual" and disconnect Knock Sensor connector.

Measure resistance between Pin No. 1 (Signal) terminal of Knock Sensor harness connector and chassis ground.

Refer to "Shop Manual" and disconnect Knock Sensor and PCM connector.

Measure resistance between Pin No. 1 (Signal) terminal of Knock Sensor harness connector and Pin No. 62 (Signal) terminal of PCM harness connector.

Is measured value within specification?

	▶ Go to "Component Inpsection" procedure.
	▶ Repair open or short in power circuit between Knock Sensor and PCM and then go to "Verification of vehicle Repair" procedure.