B003B: Second Row Right Frontal Stage 3 Deployment Control
What to do
Get this looked at promptly, and do not attempt it yourself. An airbag fault usually means the whole restraint system has switched itself off, so the airbags and pretensioners may not fire in a crash — the car drives normally and is far less able to protect you. Never probe airbag wiring with a multimeter: the current an ordinary meter uses can set off the charge. This needs a workshop with the right equipment and the correct disable procedure.
What this code means
The deployment loop for a second row right frontal airbag stage is faulty.
"Stage 1", "Stage 2" and "Stage 3" are not three airbags. They are separate charges inside one, and the module chooses how many to fire and how far apart.
That is what makes a modern frontal airbag adaptive. A bag inflated at full force is right for a severe impact and genuinely dangerous in a mild one — early single-stage designs injured people in crashes they would otherwise have walked away from. So the module decides, in the milliseconds before deployment, how hard to inflate, using crash severity, whether the belt is buckled, how far forward the seat is, and on many cars the occupant's weight from the seat sensor.
Firing two stages a few milliseconds apart gives a softer, longer inflation than firing both together. The stages are a way of varying force with a device that can only be on or off.
Which is why a fault in one stage matters even though the others are intact. The module loses its ability to choose — and rather than deploy at a force it cannot control, it will normally disable the airbag entirely.
A frontal airbag in the second or third row is unusual and tells you something about the vehicle — most often a van, minibus or large MPV where rear occupants face a seat back or a bulkhead rather than open space. The multi-stage arrangement is the same as the front, and so is the consequence of losing a stage: the module cannot choose an inflation force, so it normally disables the device rather than deploy at a force it cannot control.
Likely causes
Start here
- Corroded or loose connector · specialist
- Open circuit in the airbag deployment loop · specialist
- Faulty airbag module or initiator · specialist
Less common
- Damaged wiring under the front seats · specialist
- Faulty restraints control module · specialist
Symptoms
Components involved
Information, not instruction
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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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