W/Harness Inspection

Terminal and Connector Inspection

1. 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.
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 Vehicle Repair" procedure.
NO
1) Go to "Signal circuit Short Inspection" procedure.
Signal circuit Short Inspection
1. Ignition "OFF".
2. A/C-ECU, Driver air mix actuator : Disconnect.
3. Measure resistance between Signal (F/B) terminal of Driver air mix actuator harness connector and Signal (F/B) terminal of A/C-ECU harness connector.
A. Specification : 1 Ohm below




4. Is "resistance" display near the specified value ?
YES
1) Go to "Signal circuit Ground short Inspection" procedure.
NO
1) Check for open in harness.
2) Repair as necessary and then go to "Verification of Vehicle Repair" procedure.
Signal circuit Ground short Inspection
1. Ignition "OFF".
2. A/C-ECU : Connect, Driver air mix actuator : Disconnect.
3. Measure resistance between Signal (F/B) terminal of Driver air mix actuator harness connector and and chassis ground.
A. Specification : Infinity




4. Is "resistance" display near the specified value ?
YES
1) Go to "Power circuit Open Inspection" procedure.
NO
1) Check for short to ground in control harness.
2) Repair as necessary and then go to "Verification of Vehicle Repair" procedure.
Power circuit Open Inspection
1. Ignition "OFF".
2. A/C-ECU, Driver air mix actuator : Disconnect.
3. Measure resistance between Sensor REF (5V) terminal of Driver air mix actuator harness connector and Sensor REF (5V) terminal of A/C-ECU harness connector.
A. Specification : 1 Ohm below




4. Is "resistance" display near the specified value ?
YES
1) Go to "Power circuit Inspection" procedure.
NO
1) Check for open in harness.
2) Repair as necessary and then go to "Verification of Vehicle Repair" procedure.

Power Supply Circuit Inspection

1. Ignition "OFF".
2. A/C-ECU : Connect, Driver air mix actuator : Disconnect.
3. Ignition "ON" (ENGINE "OFF").
4. Measure voltage between Sensor REF (5V) terminal of Driver air mix actuator harness connector and and chassis ground.
A. Specification : Approx. 5V




5. Is "resistance" display near the specified value ?
YES
1) Go to "Sensor ground circuit Open Inspection" procedure.
NO
1) Check for open in harness.
2) Repair as necessary and then go to "Verification of Vehicle Repair" procedure.
Sensor ground circuit Open Inspection
1. Ignition "OFF".
2. A/C-ECU, Driver air mix actuator : Disconnect.
3. Measure resistance between Sensor ground (-) terminal of Driver air mix actuator harness connector and Sensor ground (-) terminal of A/C-ECU harness connector.
A. Specification : 1 Ohm below




4. Is "resistance" display near the specified value ?
YES
1) Go to "Component inspection" procedure.
NO
1) Check for open in harness.
2) Repair as necessary and then go to "Verification of Vehicle Repair" procedure.