Ignition "OFF"

Disconnect HO2S connector.

Measure resistance between ground terminal of HO2S(B1/S1) harness connector and chassis ground

Is resistance within the specification?

	▶ Go to "Signal circuit inspection" procedure
	▶ Repair or replace as necessary 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.

Ignition "ON" & Engine "OFF"

Measure voltage between signal terminal of HO2S(B1S1) harness connector and chassis ground

Is voltage within the specification?

	▶ Go to next step as below
	▶ Repair or replace as necessary 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.

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
	▶ Check valve timing. Refer to "P0016: Crankshaft Position-Camshaft Position Correlation(Bank1)" procedure. Repair as necessary and go to "Verification of Vehicle Repair" procedure