OBD-II · Body (B)
B0021
Left curtain airbag circuit fault
What it means
The airbag control unit has found a problem in the wiring circuit to the left curtain (head) airbag, so it may not deploy in a crash.
Symptoms
- Airbag warning light on
Likely causes, most likely first
| No. | Cause |
|---|---|
| 01 | connector disturbed during headlining, pillar trim or sunroof work |
| 02 | water ingress from a leaking sunroof drain or roof seal |
| 03 | wiring damage in the pillar |
| 04 | faulty curtain airbag |
What to check, step by step
- 01Read the fault type from the airbag module
- 02Ask about recent roof, headlining or pillar trim work
- 03Disconnect the battery and wait the specified time before touching airbag wiring
- 04Check the curtain airbag connector (usually at a pillar) and look for water marks
- 05Clear codes and confirm the airbag light goes out