B0200 code meaning
Air Bag System Voltage Out of Range
What B0200 means
B0200 is not documented in public: no publicly available J2012 list and no carmaker uses it with this meaning. What the title describes is real. An airbag control unit runs from the vehicle battery and needs a stable supply to fire reliably; Bosch rates its commercial vehicle unit for 8.5 to 32 V. An energy reserve capacitor, 2 x 4.2 mF in that unit, keeps it working for a defined autonomy time if the battery is torn off in a crash (Bosch EP1526986B1). Airbag system chips such as Bosch CG903 monitor their supply voltages and test the reserve capacitor all the time. A patent for an airbag ECU (US20140142812A1) logs how long the supply stayed in a set range, for instance during cranking dips. Outside the range the module turns on the airbag lamp, the readiness indicator FMVSS 208 demands.
B0200 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyWorkshop only
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of B0200
- Airbag warning lamp on, sometimes only after a cold start or jump start
- Other modules may also log low-voltage faults
- Safety note: airbags may not deploy while the fault is present; work on the system only with the battery disconnected and the wait time observed
Common causes of B0200
- Most likelyWeak battery or charging fault letting system voltage sag, often while cranking
- PossiblePoor ground or loose supply pin at the airbag control unit connector, or a corroded fuse contact
- Less likelyAirbag control unit faulty, for example its internal supply or reserve capacitor
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
SRS control moduleVehicle batterySRS power circuit
What each part of B0200 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). |
| 00 | The exact fault in that area. |
What to do next
- Note B0200 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 B0200
What does B0200 mean?
B0200 means "Air Bag System Voltage Out of Range". B0200 is not documented in public: no publicly available J2012 list and no carmaker uses it with this meaning. It is a generic code, so it means the same on every make.
Is it safe to drive with B0200?
B0200 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will B0200 fail an emissions test?
B0200 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 B0200 to fix?
Difficulty: workshop only. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will B0200 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.