B0168
HVAC Air Mix Door Performance
The HVAC control module has detected that the air mix (blend) door does not reach the commanded position within the expected time. The blend door regulates the ratio of air through the heater core versus around it.
- Check engine light: Not always
- Emissions related: No
- Repair difficulty: medium
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.
- Blend door actuator motor failedCommon
- Blend door mechanically binding or brokenPossible
Parts involved
- Air Mix Door Actuator
- Hvac Control Module
- Blend Door Linkage
B0168 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.