Airbag code
B0020: Side or passenger airbag circuit fault
How this range is built
| Part of the job | Low | High |
|---|---|---|
| Parts | $90 | $400 |
| Labor: 1.2 to 2 hours × $125 to $175 an hour | $150 | $350 |
| Fees: shop supplies, disposal, diagnostics | $0 | $50 |
| Total, rounded | $240 | $800 |
The hourly rate is the BLS Occupational Employment and Wage Statistics, May 2025 average pay for this trade in Boston, $31.54 an hour, times 4 to 5.5 to cover what a shop bills (overhead, tools, insurance, profit). Parts are a band from budget aftermarket to the manufacturer part. Full method.
Not a repair shop, estimates only. Typical range, estimate. Not a quote. Your car, parts and shop change the number.
This is the range for the most common fix, airbag / occupant sensor replacement. Which repair your car needs depends on a proper diagnosis.
The airbag computer sees a problem in an airbag circuit on the left side or the passenger side. Which side it refers to varies by make, so check the scan tool or manual. A loose connector or a wire pinched by a sliding seat is a common cause, and a water leak can also play a part.
- Safe to drive?
- No, get it looked at first
- Most common cause
- Loose connector under the seat
The airbag system may be turned off, so the airbags may not deploy in a crash. Get it checked soon and avoid putting children in the front seat.
What you may notice
- Airbag light on
- Passenger airbag off light odd
- Seat sensor warning
- No other symptoms
Common causes, most likely first
- Loose connector under the seat
- Damaged wiring from seat movement
- Faulty side airbag or sensor
- Water damage
- Airbag module fault
Check this first
Check the connectors under that seat for a loose fit. Leave unplugging to a shop, since airbag wires are sensitive.
Other repairs that sometimes fix B0020
| Repair | Typical range, Boston |
|---|---|
| Seat belt pretensioner / buckle replacement | $260 to $830 |
| CAN bus wiring repair | $190 to $1,275 |
| Airbag clockspring replacement | $250 to $730 |
Before you pay
- Ask the shop what test showed this part is the cause, not just that the code appeared.
- Ask for parts and labor listed separately, and for the hours.
- Ask for a written OK before any extra work. Massachusetts rules require written authorization before repairs.
Got a quote already? Check it against the range. Want to see if your car has a recall tied to this problem? Check recalls by VIN.
Need to read a code yourself? OBD-II scanners on eBay (affiliate link, disclosure).
B0020 questions
Which airbag is it?
The scan tool or repair manual tells you which side your car means. The code number alone is not always enough, since some makes use it for the left side and others for the passenger side.
Do I need a new airbag?
Often not. A connector under the seat or a damaged wire is more likely than the airbag itself. A shop should read the circuit values first, so you do not pay for a bag you do not need.
Could a seat move cause it?
Yes. Sliding the seat back and forth over time can pinch or loosen the wiring under it. If the light came on after moving the seat or cleaning under it, tell the shop.
How much does it cost to fix B0020?
The most common fix, airbag / occupant sensor replacement, has a typical range of $240 to $800 in Boston. It is an estimate built from parts prices and local labor wages, not a quote. Your car and shop change it.
Related codes
- B0001: Driver airbag circuit fault
- B1421: Restraint circuit fault (varies by make)
- B0100: Front impact sensor circuit fault
More airbag codes
Code meaning written in our own words. Some codes mean different things on different makes, so check your scan tool or manual. Not a repair shop, estimates only.