B0250
HVAC Air Temperature Internal Sensor Circuit
The HVAC controller has detected a fault in the internal cabin air temperature sensor circuit, used to regulate climate control output.
- Check engine light: Not always
- Emissions related: No
- Repair difficulty: easy
Symptoms
- Warning light or symbol related to the affected system
- Comfort or safety function impaired
Common causes
Ordered by how often each turns out to be the cause.
- Sensor element failureCommon
- Aspirator/blower fan dirtyPossible
- Open wiring to sensorPossible
Parts involved
- Cabin Air Temperature Sensor
- Hvac Control Module
B0250 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.