W/Harness Inspection

P0642 Sensor Reference Voltage \'A\' Circuit Low

Inspection/Repair - W/Harness Inspection

Terminal & 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 voltage
1. IG "OFF" and disconnect TPS, MAPS, A/C Refrigerant Pressure Sensor, Fuel Tank Pressure Sensor connector.
2. IG "ON".
3. Measure voltage between power terminal of TPS, MAPS, A/C Refrigerant Pressure Sensor, Fuel Tank Pressure Sensor harness connector and chassis ground.

Specification : Approx. 5 V








4. Is the measured voltage within specification?





Check short to ground in power circuit
1. IG "OFF" and disconnect TPS, MAPS, A/C Refrigerant Pressure Sensor, Fuel Tank Pressure Sensor connector.
2. Measure resistance between power terminal of TPS, MAPS, A/C Refrigerant Pressure Sensor, Fuel Tank Pressure Sensor harness connector and chassis ground.

Specification : Infinite








3. Is the measured resistance within specification?