Test A: DTC B1251 Or B1253 - Air Temperature Internal Sensor Circuit Open Or Short To Ground
PINPOINT TEST A: DTC B1251 OR B1253 - AIR TEMPERATURE INTERNAL SENSOR CIRCUIT OPEN OR SHORT TO GROUNDNormal Operation
Under normal operation, the in-vehicle air temperature sensor receives a ground from the electronic automatic temperature control (EATC) module through circuit RH111 (GY/BU). A 5-volt reference voltage is supplied to the in-vehicle air temperature sensor from the EATC module through circuit VH414 (GN/BU).
- DTC B1251 In-Vehicle Temperature Sensor Open Circuit - The module senses no voltage drop on the sensor reference voltage circuit, indicating an open circuit.
- DTC B1253 In-Vehicle Temperature Sensor Circuit Short to Ground - The module senses excessive voltage drop on the sensor reference voltage circuit, indicating a short directly to ground.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- In-vehicle air temperature sensor
- EATC module
A1:
A1-A3:
A3-A5:
