W/Harness Inspection

Air Conditioner

B1259 AQS Sensor Fault - 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?






Power Circuit Inspection

Check power in harness
1. Ignition "OFF"
2. Disconnect AQS sensor and Connect A/C control unit main harness connector.
3. Ignition "ON"
4. Measure voltage between Power terminal of AQS sensor harness connector and chassis ground.

Specification : approx. 12 V




5. Is the measured voltage within specification?






Signal Circuit Inspection

Check short to ground in harness
1. Ignition "OFF"
2. Disconnect AQS sensor and A/C control unit main harness connector.
3. Measure resistance between Sensor signal terminal of AQS sensor harness connector and chassis ground.

Specification : Infinity




4. Is the measured resistance within specification?