W/Harness Inspection

Engine Control
P2251 HO2S Reference Ground Circuit/Open (Bank 1 / Sensor 1) - W/Harness Inspection

Diagonostic procedure

Reference Ground Circuit Inspection
1. Ignition "OFF"
2. Disconnect HO2S and PCM connectors.
3. Measure resistance between terminals 2 of the sensor harness connector and 53 of the PCM harness connector
Specification : Approx. 0Ohms




4. Is resistance within the specification?
YES
> Go to "Terminal and Connector Inspection" procedure
NO
> Repair as necessary and go to "Verification of Vehicle Repair" procedure

Terminal and Connector Inspection

1. 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.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3. Has a problem been found?
YES
> Repair as necessary and go to "Verification of Vehicle Repair" procedure
NO
> Go to "Component Inspection" procedure