W/Harness Inspection

Power Supply Circuit Inspection

1. Ignition "OFF"
2. Disconnect HO2S sensor connector
3. Ignition "ON" & Engine "OFF"
4. Measure voltage between terminal 3 of the HO2S heater harness connector and chassis ground.
A. Specification : B+




5. Is voltage within the specification?
YES
1) Go to "Control Circuit Inspection" procedure
NO
1) Check for an open in the power supply circuit between the main relay and the HO2S.
Especially check for "SESR FUSE 10A" is installed and not blown.
Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure

CAUTION:
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.

Control Circuit Inspection

1. Measure voltage between terminal 4 of the HO2S heater harness connector and chassis ground.
A. Specification : Approx. 4-5V




2. Is voltage within the specification?
YES
1) Go to next step as below
NO
1) Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure

CAUTION:
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.

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
1) Repair as necessary and go to "Verification of Vehicle Repair" procedure
NO
1) Go to next step "Component Inspection" procedure.