OBD-II reference

All 9.533 generic OBD-II codes, explained in detail.

Causes, inspection steps and sources — a comprehensive DIY archive. Created and maintained with love for the detail. Good luck and have fun!

Body generic / SAE

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.

SystemBody
Typegeneric / SAE
GroupB0
Range / number1 / 68

Possible causes

  • Blend door actuator motor failed high
  • Blend door mechanically binding or broken medium

Symptoms

  • Warning light or symbol related to the affected system
  • Comfort or safety function impaired

Inspection / repair

  • Difficulty: medium
  • DIY: possible
  • Estimated cost: 80–800 €
  • Estimated time: 0.5–6 h
  • Component: air mix door actuator
  • Component: hvac control module
  • Component: blend door linkage

Sources

References

How to read OBD-II codes

The first letter names the vehicle system, the second digit distinguishes generic from manufacturer-specific, the remaining digits group fault area and number.

PPowertrain: engine, transmission, emissions
BBody: chassis trim, comfort, interior
CChassis: suspension, brakes, steering
UNetwork: CAN, control modules, communication