Test F: DTC B1255 OR DTC B1257 - A/C Ambient Temperature Sensor Open Circuit Or Short To Ground

PINPOINT TEST F: DTC B1255 OR DTC B1257 - A/C AMBIENT TEMPERATURE SENSOR OPEN CIRCUIT OR SHORT TO GROUND

F1:

F1-F3:

F3-F5:

F6:

Normal Operation
Under normal operation, the ambient air temperature sensor receives a ground from the dual automatic temperature control (DATC) module through circuit 9-FA49 (BN/WH). A 5-volt reference voltage is supplied to the ambient air temperature sensor from the DATC module through circuit 8-FA49 (WH/VT).

Possible Causes
- An open in circuit 9-FA49 (BN/WH) or 8-FA49 (WH/VT)
- A short to together in circuits 9-FA49 (BN/WH) and 8-FA49 (WH/VT)
- A short to ground in circuit 8-FA49 (WH/VT)
- Ambient air temperature sensor
- DATC module