What this code means
B0029 may indicate that the SRS unit is detecting a possible fault in the right side curtain airbag circuit.
What the vehicle may do
- The SRS warning indicator may be on.
- The restraint system may limit normal operation while the fault is present.
Possible fault areas
- Possible right side curtain airbag inflator circuit issue.
- Possible connector fit or terminal contact issue.
- Possible floor wire harness continuity issue.
- Possible SRS unit side concern.
Diagnostic path
Opening context
On this 2010 to 2016 Honda CR-V, B0029 points the diagnosis toward the SRS unit monitoring the right side curtain airbag circuit. In plain terms, the vehicle may be seeing a possible fault in that side curtain airbag inflator circuit, so the SRS warning indicator may be on and the restraint system may limit normal operation until the fault is handled. Broadly, this can involve the inflator circuit, connector fit, floor wire harness continuity, or the SRS unit side of the circuit. We’re going to keep the diagnosis focused on proving where that circuit fault is before replacing anything.
Safety and setup checks
Before starting, ask whether the vehicle has been in a collision. If it has, make sure the required SRS components were replaced with new parts of the correct part number and installed properly. Also handle the normal SRS safety precautions, basic troubleshooting setup, and the 12 volt battery disconnect and reconnect process before working around the airbag circuit. One more point: before condemning the SRS unit, check its software version with the HDS. If it is not at the latest version, update it and retest before going any farther with unit replacement.
First prove the fault is present
Start by clearing the DTCs with the HDS. Turn the vehicle to the ON mode and wait for 10 seconds. Then check codes again with the HDS. If B0029 is present again, the failure is duplicated and you continue into circuit testing. If B0029 is not present, treat it as an intermittent condition for now; the system is OK at this time. If a different code is present, check what that code means first instead of forcing this diagnostic path.
Simulate the right side curtain airbag inflator side
Next, move to the right side curtain airbag inflator check. Turn the vehicle to OFF, disconnect the negative cable from the 12 volt battery, and wait at least 3 minutes. Remove the headliner, then disconnect the right side curtain airbag inflator 2P connector on the floor wire harness. At that floor wire harness connector, jumper terminal No. 1 to terminal No. 2. Reconnect the negative battery cable, clear the DTCs with the HDS, turn the vehicle to ON, and wait for 10 seconds. Check for B0029 again. If the code is still indicated, continue to the open wire check. If the code is not indicated with that jumper in place, that points to a faulty right side curtain airbag; replace the right side curtain airbag, then clear the DTC.
Check the RCA positive and negative lines for an open
For the open wire check on the RCA positive and RCA negative lines, turn the vehicle OFF again. Disconnect the negative cable from the 12 volt battery and wait at least 3 minutes. Remove the jumper from the right side curtain airbag inflator 2P connector on the floor wire harness. Then disconnect SRS unit connector B, the 39P connector. At that SRS unit connector, jumper terminal No. 12 to terminal No. 13. Now measure resistance between the two terminals at the right side curtain airbag inflator 2P connector on the floor wire harness: No. 1 to No. 2.
Use the resistance result to choose the branch
With that setup, the decision point is 1.0 Ω or less. If the measurement is 1.0 Ω or less, the RCA positive and RCA negative wires are OK. At that point, check the connection at SRS unit connector B and the SRS unit. If the connection is OK, and the SRS unit software check and retest have already been handled, the diagnostic path moves to replacing the SRS unit. If the DTC still does not clear after that, replace the floor wire harness. If the resistance is not 1.0 Ω or less, there is an open in the floor wire harness; replace the floor wire harness, then clear the DTC.
Verification and takeaway
Keep the final verification separate from the testing. After the indicated correction, clear the DTC and use the same HDS check pattern to confirm B0029 does not return. The key is to prove whether the fault follows the right side curtain airbag, the floor wire harness, or the SRS unit connection and unit side before making the repair. For more diagnostic training, visit stepdiagnostics.com.
Final check
B0029 is often diagnosed by isolating the right side curtain airbag circuit from the floor harness and SRS unit side, then using the specified resistance check to choose the correct branch.
For more guided automotive diagnostics, visit STEP Diagnostics.
