OBD-II code · Body

B0021 Left Side Deployment Stage 1 Control

The SRS module has detected a fault in the deployment control circuit for the left side (driver) airbag stage 1. Side impact protection on the driver side may be reduced.

Is it safe to drive with B0021?

Usually safe for short trips, but don’t ignore it: the underlying fault can get more expensive over time.

Common causes

  • Most likelyLoose airbag connector under driver seat
  • PossibleWiring pinched in seat rail
  • Less likelySide airbag module internal fault

Symptoms

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

Repair at a glance

Difficulty
Hard
DIY friendly
Best left to a mechanic
Typical labour
0.8–3 h
Emissions test
Usually unaffected
Parts involved
Driver Side Airbag, Srs Control Module, Srs Seat Wiring

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