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?

	▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure.
	▶ Go to next step as below.

Ignition "OFF".

Disconnect HO2S connector.

Ignition "ON", Engine "OFF".

Measure voltage between VN terminal of the sensor harness connector and chassis ground.

Measure resistance between VN terminal and other terminals of the HO2S harness connector.

Is HO2S display near the specification?

	▶ Go to next step as below.
	▶ Repair open or short to ground in signal circuit and go to "Verification of Vehicle Repair" procedure. note HO2S must have a clean air reference to function properly. The air is obtained by way of the sensor wire(s). Do not attempt to repair the wire(s), connector, or the terminals.