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 "Signal Circuit Inspection" procedure.(W/O ISG) ▶ Go to "Power Circuit Inspection" procedure.(ISG)

IG "OFF".

Disconnect CKPS connector.

IG "ON" & ENG "OFF".

Measure the voltage between signal A, signal B terminal of CKPS harness connector and chassis ground.

Is the measured voltage within specification?

	▶ Go to "Check Short in signal circuit" procedure.
	▶ Go to "Check Short to ground in signal circuit" procedure.

IG "OFF".

Disconnect Knock sensor connector and ECM connector.

Measure the resistance between signal A, signal B terminal of CKPS harness connector and chassis ground.

Is the measured resistance within specification?

	▶ Repair Open in signal circuit and then, go to "Verification of Vehicle Repair" procedure.
	▶ Repair Short to ground in signal circuit and then, go to "Verification of Vehicle Repair" procedure.

IG "OFF".

Disconnect Knock sensor connector and ECM connector.

Measure the resistance between signal A, signal B terminal of CKPS harness connector.

Is the measured resistance within specification?

	▶ Go to "Component inspection" procedure.
	▶ Repair Short in signal circuit and then, go to "Verification of Vehicle Repair" procedure.

IG "OFF".

Disconnect CKPS connector.

IG "ON" & ENG "OFF".

Measure the voltage between power terminal of CKPS harness connector and chassis ground.

Is the measured voltage within specification?

	▶ Go to "Signal Circuit Inspection" procedure.
	▶ Repair or replace as necessary and then, go to "Verification of Vehicle Repair" procedure.

IG "OFF".

Disconnect CKPS connector.

IG "ON" & ENG "OFF".

Measure the voltage between signal terminal of CKPS harness connector and chassis ground.

Is the measured voltage within specification?

	▶ Go to "Ground Circuit Inspection" procedure.
	▶ Repair or replace as necessary and then, go to "Verification of Vehicle Repair" procedure.

IG "OFF".

Disconnect CKPS connector.

IG "ON" & ENG "OFF".

Measure the voltage between power terminal of CKPS harness connector and chassis ground.(A)

Measure the voltage between signal and ground terminal of CMPS harness connector and chassis ground.(B)

Is the measured voltage within specification?

	▶ Go to "Component Inspection" procedure.
	▶ Repair or replace as necessary and then, go to "Verification of Vehicle Repair" procedure.