What this code means
B0029 may indicate an open circuit or increased resistance in the right side curtain airbag first inflator circuit.
An open circuit is a break in an electrical path. Increased resistance means the path has more resistance than the procedure allows. For B0029, the path under investigation belongs to the right side curtain airbag first inflator. The diagnosis therefore needs to separate a problem associated with that component from a problem elsewhere in its circuit.
The right side curtain airbag first inflator, its connecting paths and the SRS unit are different possible fault areas. Naming the right side curtain airbag first inflator in the code does not make those possibilities interchangeable. The steps below narrow the fault area by changing a defined test condition and then checking the individual paths.
What the vehicle may do
- High detection-line voltage can trigger this code.
Possible fault areas
- Possible fault areas include the right side curtain airbag.
- The RCA+ and RCA- circuit may have a problem.
- The SRS unit may have a problem.
The procedure moves through confirmation, an indirect component check and electrical-path checks. In the indirect check, the specified jumper connection is used exactly as described. The result determines whether the component or other related parts remain involved. The later measurements examine RCA+ and RCA- through the wiring between the curtain airbag connector and SRS unit.
Read the result criteria alongside the action that produces them. During the component check, a normal circuit-test result can point to a problem with the named component. During a wire check, an abnormal reading instead points to the checked path. These conclusions belong to different stages of the diagnosis.
Diagnostic path
Understand the stored condition
B0029 identifies Open or Increased Resistance in the Right Side Curtain Airbag First Inflator. This code may point to an open circuit or increased resistance in that inflator circuit. The SRS unit monitors voltage on its internal detection line. If that voltage is higher than a specified value, the SRS unit detects an abnormality and stores the code.
Safety before troubleshooting
Follow the SRS safety precautions and procedures. Use the specified 12 volt battery terminal disconnection and reconnection procedure.
Check collision history first
Find out whether the vehicle was in a collision. If it was, make sure all required components were replaced with new components. Check that those components have the correct part number and are installed properly.
Run the confirmation procedure
Turn the vehicle to the ON mode. Wait for 10 seconds.
Check the right side curtain airbag circuit
This check evaluates the component through its related components. This check tests the related components instead. Before disconnecting the SRS related connector, follow the 12 volt battery terminal disconnection procedure. Wait for at least 3 minutes. Disconnect the right side curtain airbag inflator connector (2P). Install a jumper wire between terminals No. 1 and No. 2 of the right side curtain airbag inflator connector (2P). Turn the vehicle to the ON mode to confirm the result. Wait for 10 seconds.
For a normal result, DTC B0029-13 should not be indicated. If this check is normal, there is a problem with the right side curtain airbag. If this check is abnormal, there is a problem with other related components. Continue with the RCA+, RCA- Open Wire Inspection.
For the component test, a normal result means the stated DTC B0029-13 is not indicated after the specified test connection and confirmation. The procedure associates that normal test result with a problem in the right side curtain airbag first inflator. An abnormal result follows the branch for other related components.
Here, the word normal refers to the response of the circuit test. It does not describe a direct resistance measurement of the right side curtain airbag first inflator. The wire checks that follow use their own resistance criteria and therefore answer a different question. This distinction is the key to reading the component and circuit branches correctly.
Prepare for the open wire checks
Before disconnecting the SRS related connector, follow the 12 volt battery terminal disconnection procedure. Wait for at least 3 minutes. Disconnect SRS unit connector B (57P). Disconnect the right side curtain airbag inflator connector (2P).
Check the RCA+ wire
Check resistance in the RCA+ wire with IG Mode OFF.
- First probe: SRS unit connector B (57P) female terminal 28.
- Other probe: right side curtain airbag inflator connector (2P) female terminal 2.
- Normal reading: less than 1 ohm.
RCA+ pairs SRS unit connector B terminal 28 with curtain-airbag connector terminal 2. RCA- pairs SRS terminal 27 with airbag terminal 1. The different module terminals and airbag terminals are part of the identity of each test.
The normal resistance criterion is less than 1 ohm for each stated pair with IG Mode OFF and both connectors disconnected. This describes the connecting paths. The airbag-related conclusion comes from the separate jumper-and-confirmation test. Keeping that code result distinct from these resistance readings preserves the diagnostic reasoning before the SRS-unit assessment.
Check the RCA- wire
Check resistance in the RCA- wire with IG Mode OFF.
- First probe: SRS unit connector B (57P) female terminal 27.
- Other probe: right side curtain airbag inflator connector (2P) female terminal 1.
- Normal reading: less than 1 ohm.
If the RCA+, RCA- Open Wire Inspection is abnormal, there is a problem in the circuit.
Evaluate the SRS unit
For the SRS Unit Inspection, review the other inspection results. If the other inspection items indicated a normal condition, the remaining SRS unit is the cause. Under that condition, there is a problem with the SRS unit.
Final check
The inspection results can narrow the fault to the right side curtain airbag, its circuit, or the SRS unit.
Taken together, the results form a chain. The indirect component check establishes which branch to follow; the individual electrical checks identify an abnormal path; and the final SRS-unit conclusion depends on the earlier inspection items being normal. Keep the actual result beside the component or wire that was being checked. That makes the final decision traceable to the procedure, rather than to the wording of the stored code alone.
