B0255
HVAC Air Temperature External Sensor Circuit
A fault has been detected in the external (ambient) temperature sensor circuit used by the HVAC and instrument cluster.
A fault has been detected in the external (ambient) temperature sensor circuit used by the HVAC and instrument cluster.
Common causes
- high
Ambient sensor failure (often behind front grille)
One of the most commonly reported causes for this code — check this first.
Typical part cost: $30-170
- medium
Water in connector
A plausible cause — test and verify before replacing parts.
Typical part cost: $30-170
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First things to check
- 1Confirm the code with a scan tool and check for additional related codes.
- 2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.
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Related codes
See related trouble codes
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Frequently asked questions
What does B0255 mean?
B0255 means "HVAC Air Temperature External Sensor Circuit". It is a generic OBD-II code that points to a fault in the body.
What are the most common causes of B0255?
ambient sensor failure (often behind front grille); water in connector — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.
Can I keep driving with this code?
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical. Use the Wrenchify app for a full diagnosis specific to your vehicle.
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