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

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

C1-C3:

C3-C5:

C5-C6:

Normal Operation
Under normal operation, the A/C ambient temperature sensor receives a ground from the electronic automatic temperature control (EATC) module through circuit 3059 (YE/LG). A 5-volt reference voltage is supplied to the A/C ambient temperature sensor from the EATC module through circuit 3061 (LB/OG).

Possible Causes
- An open in circuit 3059 (YE/LG) or 3061 (LB/OG)
- A short together in circuit 3059 (YE/LG) and 3061 (LB/OG)
- A short to ground in circuit 3061 (LB/OG)
- A/C ambient temperature sensor
- Electronic automatic temperature control (EATC) module