Test B: DTC B1251 or DTC 1253 - A/C In-vehicle Temperature Sensor Open Circuit or Short to Ground

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

B1:

B1-B3:

B3-B5:

B5-B6:

Normal Operation
Under normal operation, the in-vehicle air temperature sensor receives a ground from the dual automatic temperature control (DATC) module through circuit 470 (PK/BK). A 5 volt reference voltage is supplied to the in-vehicle air temperature sensor from the DATC module through circuit 788 (RD/OG).

Possible Causes
- An open in circuit 470 (PK/BK) or 788 (RD/OG).
- A short to voltage in circuit 470 (PK/BK).
- A short to ground in circuit 788 (RD/OG).
- In-vehicle air temperature sensor.
- DATC module.