B1C29

Symptoms

• The airbag fault light on the dashboard is on
• The airbag system is completely or partially disabled
• The car cannot be unlocked due to a security error
• There is a delay or lack of ACU self-test when attempting to start the engine.

Causes

• Broken wire harness to chest airbag squib
• Oxidation or corrosion of squib connector contacts
• Faulty or burnt out squib
• Poor contact in connections between ACU and squib
• Damage to the airbag system wiring harness connector
• Incorrect installation after body repair or replacement of the left seat
• Airbag control module (ACU) malfunction
• Airbag fuse blown or damaged

How to Fix

1. Connect an OBD-II diagnostic scanner to confirm the B1C29 code and obtain additional information about the malfunction
2. Disconnect the airbag system and battery for 15 minutes (disposal procedure)
3. Visually inspect the wiring harness leading to the left seat for damage, breaks or kinks.
4. Check the squib connector for oxidation, rust or loose contacts; clean contacts if necessary
5. Measure the resistance of the squib circuit with an ohmmeter (usually should be 1-3 Ohms, depending on the model)
6. Disconnect and reconnect all connectors in the airbag circuit, ensuring a tight fit.
7. Replace the squib if its resistance is outside the acceptable limits or if it appears damaged
8. Reconnect the battery and run the airbag system self-test via scanner
9. Clear the error code and carry out a test run to check that the code does not trigger again

Related codes

FAQ