B0039Second Row Right Frontal Stage 1 Deployment Control
- Generic OBD-II code · Body
- How the car detects it
- B0039 belongs to the right-hand rear-seat frontal airbag, stage 1, which is the primary charge that the module fires in any frontal crash severe enough to need the bag. The bag sits in the back of the passenger seat ahead; Mercedes-Benz offers this layout as an S-Class option and fits it as standard to the Maybach, where it is meant to ease head and neck loads on belted outer rear passengers. An older Daimler application already described a bag at the rear of a front seat that spreads a channel frame and fills with ambient air. No public DTC table pairs B0039 with this bag. GM Global A modules use B0039 for the right rear belt pretensioner instead (Saab 9-4X 2011). Airbag lamp on.
- What you may notice
- Airbag warning lamp on
- Right rear passenger may lose frontal airbag protection
- 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
- LikelyLoose or corroded connector of the airbag lead routed through the front seat backrest
- PossibleInternal fault in the right rear-seat airbag module
- PossibleLead stretched or pinched by the seat track or folding mechanism
- 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.