What B0020 means
The airbag computer has found a fault in the circuit that fires a left-side airbag or seat belt pretensioner, depending on the vehicle. Until it's repaired, that part may not work in a crash, and the airbag warning light stays on. A damaged connector or wiring under the driver's seat is the usual cause.
How the engine computer detects it
Left Side Deployment Control: the restraints module has detected a fault in this airbag/pretensioner deployment circuit, which may prevent correct deployment in a crash. Safety-critical.
Written from public technical sources and not yet checked by a mechanic. How we write these pages
Symptoms
- Warning light or symbol related to the affected system
- Comfort or safety function impaired
Common causes
- Seat harness connector under driver seat damaged Most likely
- Side airbag squib circuit open Possible
- SRS control module fault Less likely
How to diagnose B0020
- Think back to whether the light came on after the seat was moved, cleaned under, removed or worked on, and tell the shop. It helps them find the cause.
- Don't unplug, probe or spray anything on the yellow connectors under the seat or near the airbags.
- Check for open recalls on your vehicle with your VIN at nhtsa.gov/recalls.
- Have the code read with a scanner that reads the airbag (SRS) module. Basic code readers can't see it.
- A shop will inspect the seat harness and the side airbag circuit, repair the wiring or replace the faulty part, then clear the code with a scanner.
Vehicles that report B0020 most
| Vehicle | Years | Reports | Share | Median miles |
|---|---|---|---|---|
| Nissan Altima | 2013–2018 | 23 | — | |
| Chrysler 200 | 2015–2016 | 5 | — | |
| Honda Accord | 2018–2020 | 4 | — | |
| Jeep Cherokee | 2015–2016 | 3 | — |
Counts of owner complaints to the NHTSA that mention B0020 (57 in total), not failure rates: popular models get more complaints simply because more of them are on the road. Models with fewer than 3 complaints are left out.
Reading the code
- B
- Body
- 0
- Generic (SAE) code
- 020
- Specific fault
Questions drivers ask
Can I drive with code B0020?
The car drives normally, but you have less crash protection on the driver's side until this is fixed, so get it repaired soon. Don't try to fix it yourself: airbag parts can deploy unexpectedly and cause serious injury.
Often reported together
Codes that owners mention in the same NHTSA complaints as B0020. They can point to a shared cause, so it's worth checking them together.
This page is general information, not a substitute for a professional diagnosis. Repair costs are rough estimates for parts and labor and vary by vehicle and region.