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?
YES
Repair as necessary and go to "Verification of Vehicle Repair" procedure.
NO
Go to "Knock sensor circuit inspection" procedure.
Check Short to Voltage in signal circuit
Key "OFF".
Disconnect Knock sensor connector.
Key "ON" & ENG "OFF"
Measure the voltage between terminal 1 of knock sensor harness connector and chassis ground.
Specification : Approx 0V
Is the measured voltage within specification ?
YES
Go to "Check Short to ground in signal circuit" procedure.
NO
Repair Short to Power in signal circuit and then, go to "Verification of Vehicle Repair" procedure.
Check Shrot to ground in signal circuit
Key "OFF".
Disconnect Knock sensor connector and ECM connector.
Measure the resistance between terminal 1 and 2 of knock sensor harness connector.
Specification : Infinite
Is the measured resistance within specifications?
YES
Go to "Check Open in signal circuit" procedure.
NO
Repair Short to ground in signal circuit and then, go to "Verification of Vehicle Repair" procedure.
Check Open in signal circuit
Key "OFF".
Disconnect Knock sensor connector and ECM connector.
Measure the resistance between terminal 1 of knock sensor harness connector and terminal 19 of ECM harness connector.
Specification : Below 1Ω
Is the measured resistance within specifications ?
YES
Go to "Check Open in ground circuit" procedur.
NO
Repair Open in signal circuit and then, go to "Verification of Vehicle Repair" procedure.
Check Open in ground circuit
Key "OFF".
Disconnect Knock sensor connector and ECM connector.
Measure the resistance between terminal 2 of knock sensor harness connector and ground.
Specification : Below 1Ω
Is the measured resistance within specifications ?
YES
Go to "Component inspection" procedure.
NO
Repair Open in ground circuit and then, go to "Verification of Vehicle Repair" procedure.