B0168HVAC Air Mix Door Performance
- Generic OBD-II code · Body
- How the car detects it
- B0168 shows up neither in the publicly available J2012 lists nor, with this meaning, in public carmaker documents; air mix door circuits have the codes B0258 and B0263. The air mix or blend door divides the airflow, sending part across the heater core and part past it, and so sets outlet temperature. A performance fault means it does not reach or hold its target. An older Japanese patent (CA1266779A) shows how sensitive this is: in the door range where a small movement changes air temperature a lot, the motor gets lower voltage to stop the door hunting. In US5529112A the temperature door motor runs into its end stop and stays stalled there. GM's Global A climate control drives this door with a stepper motor and logs it under B0408.
- What you may notice
- Outlet air stays hot or cold regardless of the temperature setting
- Temperature swings or clicking behind the dash
- Likely causes
- LikelyBlend door shaft or lever broken or slipping on the actuator
- PossibleAir mix actuator gear worn or motor weak
- RareForeign object or debris in the HVAC case blocking the door
- Repair
- Medium · Often possible to do yourself.Typical cost: €60 – €800
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.