3.
Has a problem been found?
 | ▶ Repair as necessary and then go to "Verification of Vehicle Repair" procedure. |
 | ▶ Go to "Ground Circuit Inspection" procedure. |
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 switch "OFF"
Disconnect battery (-) cable.
Refer to "Shop Manual" and disconnect Upstream O2 Sensor connector.
Measure the resistance between Pin No. 2 (Ground) terminal of upstream O2 sensor harness connector and chassis ground.
Specification : Approx. below 1 Ω
Refer to "Shop Manual" and disconnect ECM/PCM connector.
Measure the resistance between Pin No. 2 (Ground) termianl of upstream O2 sensor harness connector and Pin No. 25 (Ground) terminal of ECM/PCM harness connector.
Specification : Approx. below 1 Ω
Is the measured value within specification?
| ▶ Go to "Signal Circuit Inpsection" procedure. |
| ▶ Repair open or short in ground circuit between Upstream O2 Sensor and ECM and then go to "Verification of vehicle Repair" procedure. |
Ignition switch "OFF"
Refer to "Shop Manual" and disconnect Upstream O2 Sensor connector.
Ignition switch "ON"
Measure the voltage between Pin No. 1 (Signal) terminal of upstream O2 Sensor harness connector and chassis ground.
Specification : Approx. 0.45V
Is the measured value within specification?
| ▶ Go to "Component Inpsection" procedure. |
| ▶ Repair open or short in signal circuit between Upstream O2 Sensor and ECM and then go to "Verification of vehicle Repair" procedure. |
