Ignition "OFF".

Disconnect Knock sensor and PCM connector.

Measure resistance of the ground circuit between the sensor connector and the PCM connector.

Is resistance within the specification ?

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

Check for short to ground in signal circuit.

(2)

Is resistance within the specification ?

	▶ Go to next step as below.
	▶ Check signal circuit for short to ground. Repair as necessary and go to "Verification of Vehicle Repair" procedure.

Check for short to power in signal circuit.

(4)

Is voltage within the specification ?

	▶ Go to next step as below.
	▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure.

Check for open in signal harness.

(3)

Is resistance within the specification ?

	▶ Go to next step as below.
	▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure.

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 go to "Verification of Vehicle Repair" procedure.
	▶ Go to next step as below.