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?
YES
▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure
NO
▶ Go to "Control Circuit Inspection" procedure.
Check for open in control harness.
Ignition "OFF".
Disconnect HO2S and PCM connectors
Measure resistance between terminals 3 of the HO2S heater harness connector and 8 of the PCM harness connector.
Specification : Approx 0Ω
Is resistance within the specification?
YES
▶ Go to next step as below
NO
▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure.
Check for short to battery in control circuit.
Reconnect the PCM connector.
Ignition "ON" & Engine "OFF"
Measure voltage between terminal 3 of the HO2S heater harness connector and chassis ground.
Specification : Approx 0V
Is voltage within the specification?
YES
▶ Go to "Component Inspection" procedure
NO
▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure.
