OBD-II code · Body
B0258 HVAC Air Mix Door 1 Circuit
The HVAC controller reports a fault in the actuator circuit for air mix door 1, which controls the proportion of warm and cool air in the airflow.
Is it safe to drive with B0258?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyAir mix door actuator motor failed
- PossibleMix door jammed by debris
- PossibleOpen wiring to actuator
Symptoms
- Warning light or symbol related to the affected system
- Comfort or safety function impaired
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 1–4 h
- Emissions test
- Usually unaffected
- Parts involved
- HVAC Air Mix Actuator, HVAC Control Module
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.