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?

YES

▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure.

NO

▶ Go to "Ground Circuit Inspection" procedure.

Ignition "OFF".

Disconnect Knock sensor connector.

Measure resistance between terminals 1 of the sensor harness connector and 32 of the ECM harness connector.

Specification : Approx. 0Ω

Is resistance within the specification?

YES

▶ Go to "Signal Circuit Inspection" procedure.

NO

▶ Check for an open in the ground circuit. Repair as necessary and go to "Verification of Vehicle Repair" procedure.

Check for open in signal harness.

(2)

Measure resistance between terminals 2 of the sensor harness connector and 31 of the ECM harness connector.

Specification : Approx. 0Ω

Check for short to ground in signal harness.

(2)

Measure resistance between terminal 2 of the sensor harness connector and chassis ground

Specification : Infinite

Check for short to power in signal harness.

(4)

Measure voltage between terminal 2 of the sensor harness connector and chassis ground

Specification : Approx. 0V