Passenger Seat Belt Switch Circuit
Issues detected in the passenger seat belt switch circuit.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The passenger seat belt switch is not working properly, meaning it can't tell if the seat belt is buckled or not, which might cause warning lights or chimes.
What the computer is actually seeing
The airbag control module sees an abnormal voltage or resistance level in the passenger seat belt switch circuit, indicating a fault.
What a healthy reading looks like
The switch should show 0 volts when unbuckled (open circuit) and close to battery voltage (around 12V) when buckled (closed circuit).
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 1Inspect the passenger seat belt switch and harness for visible damage or disconnection.
- 2Test the seat belt switch with a multimeter; expect 0 volts when unbuckled and battery voltage when buckled.
- 3Check the wiring and connectors for short circuits or corrosion; look for pinched wires or frayed insulation.
- 4If everything checks out, consider testing or replacing the airbag control module.
Common causes
- Faulty seat belt switch
- Damaged wiring or connectors
- Corroded terminals
- Faulty airbag control module
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's generally safe to drive, but the airbag system may not deploy properly in an accident.
Will this code come back after clearing?
It can come back if the fault isn't fixed, so you need to diagnose and repair the issue.
Why does this code appear with B0004?
B0004 also relates to seat belt systems, indicating multiple issues may be present.
Working a real vehicle right now?
Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.
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