OBD-II trouble code
B0028: Right Side Airbag Deployment Control (Subfault)
The airbag/SRS control module detected an electrical fault in the right-side airbag deployment loop. The right seat-mounted side airbag may not deploy as designed, so this needs prompt professional attention.
Quick facts
- System
- Body
- Category
- Airbag / SRS Restraints
- Severity
- High severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $100 – $900
- DIY difficulty
- Shop recommended
What does B0028 mean?
B0028 is a body (B) code stored by the airbag control module. Its SAE-generic definition is 'Right Side Airbag Deployment Control,' referring to the firing loop that deploys the right-side (front passenger) side-impact airbag — typically the thorax/torso airbag mounted in the outboard edge of the passenger seat. It is the right-side mirror of B0020 (Left Side Airbag Deployment Control). The module monitors this loop continuously and stores B0028 when its electrical condition is out of specification. As with all B-codes, confirm the exact application against your make's service data.
The module sets the code when the deployment loop's resistance falls outside the tight window these pyrotechnic circuits require — an open circuit, a short to power or ground, or resistance that is too high or too low. A symptom byte appended to the code identifies the exact fault type. Because the side airbag is built into the passenger seat, its firing loop passes through a connector under the seat, where the harness flexes every time the seat slides. That under-seat connector is a well-known trouble spot: dropped items, spills, foot traffic, and repeated seat movement all work the connector loose or corrode its terminals over time.
This is a supplemental restraint fault, not a driveability fault: the vehicle drives normally, but the right side airbag may not deploy as intended in a side impact, and airbag circuits carry a small risk of unintended deployment when mishandled. SRS diagnosis and repair should be performed by a qualified technician who can safely disable the system, and the fault should not be left unrepaired.
Common causes
- Corroded, backed-out, or loose connector under the passenger seat (most common cause)
- Damaged seat harness from repeated seat travel or an item pinched under the seat
- Failed seat-mounted side airbag inflator (squib)
- Fault in the SRS connector or its shorting bar at the airbag
- Moisture or a spill reaching the under-seat connector
- Faulty airbag/SRS control module
Symptoms
- Airbag / SRS warning light on
- Stored B0028 fault (often with a symptom byte) in the restraints module
- No effect on engine or driving performance
- Fault may come and go as the seat is moved, if the under-seat connector is loose
Diagnostic steps
- 1.Use a scan tool that can access the airbag/SRS module and record B0028 with its full symptom byte and any companion codes.
- 2.Confirm the right side airbag loop routing and connector location for the specific make and model.
- 3.With the system safely disabled per service procedure, inspect the connector under the passenger seat for corrosion, backed-out terminals, or a backed-out connector position assurance (CPA) lock.
- 4.Wiggle-test the seat harness and slide the seat through its travel to reproduce an intermittent fault.
- 5.Measure the deployment-loop resistance against specification to separate a wiring/connector fault from a failed inflator.
- 6.If the airbag or module was recently replaced, verify the correct part and proper programming.
- 7.Repair the wiring/connector fault or replace the indicated component, then clear codes and confirm the SRS light stays off.
Repair cost
$100 – $900
Re-seating or repairing an under-seat connector can be inexpensive, while a failed seat airbag inflator or control module is much costlier. SRS diagnostic time typically runs $100-$200, and a seat side airbag or SDM/RCM replacement with programming can reach several hundred dollars or more. SRS work should be done by a qualified technician.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with airbag control module (sdm) replacement / reset preselected. Adjust labor rate and vehicle category to fit your situation.
DIY vs shop
Leave this one to a qualified shop. It typically involves emissions-critical components, refrigerant handling, or other work that requires manufacturer-grade tooling, training, or certification. DIY attempts often produce a more expensive problem than the original code.