Many malfunctions in the electrical system are caused by poor harness and terminals.
Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
Thoroughly check all connectors (and connections) for looseness, bending, corrosion, contamination, deterioration, and/or damage.
Has a problem been found?
![]() | ▶ Repair as necessary and then go to "Verification of Vehicle Repair" procedure. |
![]() | ▶ Go to "Ground Circuit Inspection" procedure. |
Ignition "OFF".
Disconnect Battery (-) terminal.
Refer to "Shop Manual" and disconnect Downstream O2 Sensor connector.
Measure resistance between Pin No. 2 (Ground) terminal of Downstream O2 Sensor harness connector and chassis ground.
Specification : Approx. below 1Ω
Is measured value within specification?
![]() | ▶ Go to "Signal Circuit Inpsection" procedure. |
![]() | ▶ Repair open or short in ground circuit between Downstream O2 Sensor and PCM and then go to "Verification of vehicle Repair" procedure. |
Ignition "OFF".
Refer to "Shop Manual" and disconnect Downstream O2 Sensor connector.
Ignition "ON".
Measure voltage between Pin No. 1 (Signal) terminal of Downstream O2 Sensor harness connector and chassis ground.
Specification : Approx. 0.5 V
Is measured value within specification?
![]() | ▶ Go to "Component Inpsection" procedure. |
![]() | ▶ Repair open or short in signal circuit between Downstream O2 Sensor and PCM and then go to "Verification of vehicle Repair" procedure. |