B0049 code meaning
Third Row Right Frontal Stage 1 Deployment Control
What B0049 means
B0049 marks the stage 1 charge of a right third-row frontal bag, the main charge of a bag that would have to come out of the second-row seatback ahead of it. Daimler's application for a bag mounted behind a front seat and Mercedes-Benz's later design with chambers that bridge a changing seat gap show how such a bag can be built; in series, Mercedes offers rear frontal airbags only for the outer second-row seats of its S-Class and Maybach models. No carmaker documents B0049 and no bulletin cites it. A third-row frontal code on a vehicle without that equipment points to a module set up for the wrong variant. Airbag lamp on.
B0049 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyWorkshop only
- Typical labor1 to 4 hours
- Clears after repairWhen cleared with a scanner
Symptoms of B0049
- Airbag warning lamp on
- Frontal airbag for the right third-row seat may not deploy
- Safety note: do not probe the airbag circuit yourself; unplug airbag connectors only with the battery disconnected and the stated wait time observed
Common causes of B0049
- PossibleLoose connector of the airbag lead in the second-row seatback
- PossibleLead strained when the second-row seat is folded or slid
- Less likelyRestraint module configured for equipment the vehicle does not have (wrong part or coding)
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Third row right frontal airbagSquib circuitSRS seat wiringSRS control module
What each part of B0049 means
| B | Body system: airbags, seat belts, power seats, lights and climate control. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 49 | The exact fault in that area. |
What to do next
- Note B0049 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about B0049
What does B0049 mean?
B0049 means "Third Row Right Frontal Stage 1 Deployment Control". B0049 marks the stage 1 charge of a right third-row frontal bag, the main charge of a bag that would have to come out of the second-row seatback ahead of it. It is a generic code, so it means the same on every make.
Is it safe to drive with B0049?
B0049 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will B0049 fail an emissions test?
B0049 is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is B0049 to fix?
Difficulty: workshop only. A typical repair takes 1 to 4 hours of work. This is a job for a workshop.
Will B0049 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.