B004AThird Row Right Frontal Stage 2 Deployment Control
- Generic OBD-II code · Body
- How the car detects it
- B004A is the second-stage loop of the right third-row frontal airbag. Stage 2 is a separately ignited charge: Breed's patent shows an inflator whose chambers each carry their own igniter, fired alone, together or with a delay chosen by the controller, and Mercedes-Benz's rear airbag filing allows one deployment device per chamber for sequential filling. No published DTC table, vehicle maker or bulletin connects B004A to a real vehicle. If it appears, the stage 2 circuit of that bag is out of range while stage 1 (B0049) may still be fine; the left-hand equivalent is B0042. Airbag lamp on.
- What you may notice
- Airbag warning lamp on
- Two-stage inflation for the right third-row seat is lost
- Safety note: do not probe the airbag circuit yourself; unplug airbag connectors only with the battery disconnected and the stated wait time observed
- Likely causes
- PossibleOpen or short only in the stage 2 wiring
- PossibleLoose connector in the second-row seatback
- RareRestraint module configured for equipment the vehicle does not have (wrong part or coding)
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €100 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.