Test D: DTC B1251 OR DTC 1253 - A/C In-Vehicle Temperature Sensor Open Circuit or Short to Ground

PINPOINT TEST D: DTC B1251 OR DTC 1253 - A/C IN-VEHICLE TEMPERATURE SENSOR OPEN CIRCUIT OR SHORT TO GROUND

D1:

D1-D3:

D3-D5:

D5-D6:

Normal Operation
Under normal operation, the in-vehicle temperature sensor receives a ground from the dual automatic temperature control (DATC) module through circuit 9-FA48 (BN/GN). A 5-volt reference voltage is supplied to the in-vehicle temperature sensor from the DATC module through circuit 8-FA48 (WH/GN).

Possible Causes
- An open in circuit 9-FA48 (BN/GN) or 8-FA48 (WH/GN)
- A short together in circuits 9-FA48 (BN/GN) and 8-FA48 (WH/GN)
- A short to ground in circuit 8-FA48 (WH/GN)
- DATC module
- In-vehicle air temperature sensor