What this code means
B0028 may indicate an SRS concern in the front passenger’s side airbag inflator circuit, often involving an open circuit or increased resistance condition.
What the vehicle may do
- The SRS warning light may be on.
- The restraint system may limit normal airbag operation while the fault is present.
Possible fault areas
- Front passenger’s side airbag inflator circuit
- Inflator connector or connection condition
- Right side wire harness
- SRS unit connector area
- SRS unit or SRS unit software status
- Possible prior collision repair concerns
Diagnostic path
Open and code meaning
On this Accord, B0028 is an SRS code for the front passenger’s side airbag inflator circuit. In plain language, the SRS unit may be seeing an open circuit or increased resistance on that passenger-side inflator path. The vehicle may turn on the SRS warning light, and the restraint system may limit how it operates until the fault is corrected. The broad fault areas can include the airbag inflator connection, the right side wire harness, the SRS unit connector, the SRS unit itself, or a collision repair issue if the vehicle has been hit before. Before you get into testing, make sure you’re using the required SRS inflator simulator and SRS simulator lead L, follow SRS precautions, and handle the battery disconnect and reconnect procedure correctly.
Start with verification
Start by verifying the fault. Clear the DTCs with the HDS. Turn the vehicle to ON mode, wait for 10 seconds, then check for DTCs again with the HDS. If B0028-13 comes right back, the failure is duplicated and you move into circuit testing. If it does not come back, treat it as an intermittent at that moment. If other codes are present, check what they mean first instead of chasing this one in isolation.
Substitute the inflator with the simulator
Next, isolate the front passenger’s side airbag inflator from the rest of the circuit. Turn the vehicle OFF, disconnect the negative cable from the 12 volt battery, and wait at least 3 minutes. Disconnect the front passenger’s side airbag inflator 2P connector on the right side wire harness. Connect SRS simulator lead L to the SRS inflator simulator using the 2 Ω connectors, then connect that lead to the front passenger’s side airbag inflator 2P connector on the right side wire harness. Reconnect the negative battery cable, clear the DTCs, turn the vehicle to ON mode, wait for 10 seconds, and check for DTCs with the HDS. If B0028-13 is no longer indicated with the simulator in place, the path points to an open in the front passenger’s side airbag inflator, and the supported repair path is to replace the front passenger’s side airbag, then clear the DTC. If the code is still indicated, keep going because the fault is still present outside the inflator itself.
Check the RSA circuit for an open
Now check the RSA plus and RSA minus lines for an open. Turn the vehicle OFF again, disconnect the negative cable from the 12 volt battery, and wait at least 3 minutes. Disconnect SRS unit connector B, the 39P connector. Then disconnect the SRS inflator simulator from SRS simulator lead L, but leave SRS simulator lead L connected to the front passenger’s side airbag inflator 2P connector on the right side wire harness. With the vehicle OFF, the passenger inflator connector disconnected from the airbag side, SRS unit connector B disconnected, and simulator lead L still connected to the harness connector, measure resistance at the black terminal of SRS simulator lead L. The decision point is 1.0 Ω or less.
Use the resistance result
If the measurement is not 1.0 Ω or less, the diagnostic path identifies an open in the right side wire harness. The supported repair path is to replace the right side wire harness, then clear the DTC. If the measurement is 1.0 Ω or less, the RSA plus and RSA minus wires are considered OK. At that point, look hard at the SRS unit connector B connection and the SRS unit side. Before replacing the SRS unit, check the SRS unit software version with the HDS. If it is not the latest version, update the SRS unit software and retest. If the connection is OK and the path still supports it, replace the SRS unit. If the DTC does not clear after that, the path moves to replacing the right side wire harness. If the exact connector-check detail is not clear during the job, do not guess. Pause, recheck the earlier diagnostic path, and make sure the connector inspection is solid before condemning a module.
Verify separately
Keep the verification separate from the testing. After the branch-supported correction, clear the DTCs with the HDS, turn the vehicle to ON mode, wait for 10 seconds, and confirm B0028-13 stays gone. The takeaway is simple: prove the code first, substitute the inflator with the correct SRS simulator, then use the RSA circuit resistance check to separate an inflator fault from a harness, connector, software, or SRS unit path. For more diagnostic training, visit stepdiagnostics.com.
Final check
B0028 often needs a careful SRS circuit diagnosis that separates the possible inflator circuit, harness, connector, software status, and SRS unit areas.
For more guided automotive diagnostics, visit STEP Diagnostics.
