W/Harness Inspection

Air Conditioner

Air Conditioner - B1257 AQS Sensor Open - 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?






Signal Circuit Inspection

Check for open in harness
1. Ignition "OFF".
2. Disconnect AQS sensor.
3. Measure resistance between terminal "4" of AQS sensor and terminal "2" of A/C Control Unit.

Specification : Approx. 0 Ohms




4. Is the measured resistance within specifications?






Ground Circuit inspection

Check for open in ground harness
1. Ignition "OFF".
2. Disconnect AQS sensor.
3. Measure resistance between terminal "5" of AQS sensor and chassis ground.

Specification : Approx. 0 Ohms




4. Is the measured resistance within specifications?






Power Supply Circuit Inspection

Check for open or short in ground harness
1. Ignition "OFF".
2. Disconnect AQS sensor.
3. Measure voltage between terminal "6" of AQS sensor and chassis ground.

Specification : 9 - 16 V




4. Is the measured resistance within specifications?