W/Harness Inspection

Ground circuit inspection

1. Ignition "OFF"
2. Disconnect Knock sensor and PCM connectors
3. Measure resistance between ground terminal of the sensor harness connector and Knock signal of the PCM harness connector.

Specification : Approx. 0 Ohm





4. Is resistance within the specification?






Signal Circuit Inspection

1. Check for short to ground in signal circuit
(1) Ignition "OFF"
(2) Disconnect Knock sensor and PCM connectors
(3) Measure resistance between signal terminal of the sensor harness connector and chassis ground.

Specification : Infinite





(4) Is resistance within the specification?





2. Check for short to power in signal circuit
(1) Disconnect Knock Sensor connector
(2) Ignition "ON" & Engine "OFF"
(3) Measure voltage between signal terminal of sensor harness connector and chassis ground.

Specification : Approx. 0V





(4) Is voltage within the specification?





3. Check for open in signal harness
(1) Ignition "OFF"
(2) Measure resistance between signal terminal of sensor harness connector and Knock signal terminal of the PCM harness connector.

Specification : Approx. 0 Ohm





(3) Is resistance within the specification?






Terminal and Connector Inspection

1. 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.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration or damage.
3. Has a problem been found?