Many malfunctions in the electrical system are caused by poor harness(s) and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
Check the following conditions:
Check for damaged harness and terminals: contact resistance, oxidation, bent or broken terminals.
Check for poor connection between ECM and component: backed out terminal, improper mating, broken locks or poor terminal to wire connection
Use a suitable male pin to ensure that contact in sockets is good. The pin should remain in position when pulled gently.
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 terminal 1 of the sensor harness connector(C38-1) and ECM(30/C23-3)
Specification : Approx. 0Ω
Is resistance near the specified value?
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
Ignition "OFF"
Measure resistance between terminal 2 of sensor harness connector(C38-1) and ECM(29/C23-3)
Specification : Approx. 0Ω
Is resistance within specification?
YES
Go to next step.
NO
Repair as necessary and go to "Verification of Vehicle Repair" procedure.
Ignition "OFF"
Measure resistance between terminal 2 of sensor harness connector(C38-1) and chassis ground
Specification : Infinite
Is resistance within specification?
YES
Go to next step.
NO
Repair as necessary and go to "Verification of Vehicle Repair" procedure.
Ignition "OFF"
Disconnect ECM connector
Ignition "ON" & Engine "OFF"
Measure voltage between terminal 2 of sensor harness connector(C38-1) and chassis ground
Specification : Approx. 0V
Is voltage within specification?
YES
Go to "Component Inspection" procedure.
NO
Repair as necessary and go to "Verification of Vehicle Repair" procedure.
