OBD-II code · Body

B0173 HVAC Air Inlet Door

The HVAC control module has detected a fault on the fresh-air/recirculation inlet door — typically a stuck actuator or position feedback out of range.

Is it safe to drive with B0173?

Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.

Common causes

  • Most likelyInlet door actuator failed
  • PossibleInlet door mechanically binding

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
0.5–3 h
Emissions test
Usually unaffected
Parts involved
Air Inlet Door Actuator, HVAC Control Module

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.