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 "Signal Circuit Inspection" procedure.

Ignition "OFF"

Disconnect HO2S connector.

Measure resistance between terminal 1 of the sensor harness connector and chassis ground.

Specification : Infinite

Is resistance within the specification?

YES

▶ Go to "Component Inspection" procedure

NO

▶ Repair open or short to ground in signal circuit and go to "Verification of Vehicle Repair" procedure.