B00B0: Driver Seat Occupant Classification Sensor A
What to do
The passenger airbag may stay switched off. Try removing any seat cover, cushion or heater pad — these sensors weigh the seat and anything added confuses them. If the seat has been removed or replaced recently, it probably needs recalibrating.
What this code means
The driver seat occupant classification sensor A circuit is faulty.
Occupant sensing exists because a deploying airbag is dangerous to somebody in the wrong place, and the system has to know who is in the seat before it decides what to do.
The problem it solves is real and was learned expensively. Early airbags deployed at one force regardless of who was there, and they injured and killed children and small adults in crashes that would otherwise have been survivable. A bag inflating at three hundred kilometres an hour into someone sitting close to it is a weapon, which is why the industry moved to systems that can soften, delay or suppress deployment.
Two quite different questions are being asked, and the standard gives them separate codes. Classification asks who — an adult, a small adult, a child, a child seat, or an empty seat — and is answered mostly by weight. Position asks where — how far the occupant is from the airbag, and whether they are leaning into its path.
Both matter because either alone gives wrong answers. A heavy adult leaning forward is in as much danger from the bag as a light one sitting normally, and weight cannot see that.
Five sensors under one seat is a pattern, not five attempts at the same reading. Weight alone cannot distinguish a child seat strapped down hard from a small adult, but the distribution of that weight across the cushion can — a person's weight sits in two concentrated areas, a child seat's spreads across a rigid base.
Which is why losing one sensor matters more than losing one fifth of the information. The pattern is what the classification rests on, and a missing element leaves it ambiguous rather than merely less precise. The system falls back to the safe assumption and usually suppresses the airbag.
The wiring is the usual suspect. These sensors sit in a mat under the cushion with a harness that flexes every time the seat moves, and it is routinely damaged by objects pushed underneath.
Likely causes
Start here
- Damaged wiring under the front seats · specialist
- Faulty occupant classification module · specialist
- Corroded or loose connector · specialist
Less common
Symptoms
Components involved
Information, not instruction
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Community experience
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