B1129: Front Right Side Airbag Circuit Open

Circuit fault

What B1129 means

The control unit pushes a small test current through each firing loop and watches the resistance that comes back. Open means the current found no path at all. For B1129 that loop runs from the module, through the harness under the carpet, up into the passenger seat, and into the inflator in the seat back. A break anywhere along it reads the same way.

Seat mounted airbag circuits fail more often than dash circuits because the wiring moves. Every time the seat slides forward and back, the harness underneath it flexes. Connectors under seats also sit where feet, cargo, and cleaning water reach them. The module cannot tell you where the break is, only that the loop no longer completes.

Common causes

• The yellow connector under the passenger seat unplugged or not latched after seat removal
• Harness wear where the wiring flexes as the seat travels forward and back
• A broken wire inside the seat back where it passes into the inflator
• Corroded terminals from spilled liquid or a wet carpet under the passenger seat
• An inflator that has failed open internally
• Module pin damage at the connector after a previous repair

Crash data or hardware fault?

B1129 is a live circuit reading, so it behaves nothing like stored crash data. The module rechecks the loop constantly and the code clears on its own once resistance returns to normal. Crash data, by contrast, is written after a deployment and no amount of scanning or key cycling removes it.

Does our reset clear it?

Do not expect a reset to solve B1129. The module is reporting an open circuit it is measuring right now, so erasing the code leaves the open in place and the code comes back within seconds. Find the break first. If the vehicle deployed and the module is locked with crash data as well, that part is what our mail-in reset service handles.

Which makes throw it

Both Infiniti and Nissan use B1129 for the front right side airbag loop, and the circuit is laid out the same way on both: module, floor harness, seat connector, inflator.

What to do next

Look under the passenger seat first and confirm the yellow connector is seated and locked, because a seat that was removed for any reason is the usual reason this code exists. Next, slide the seat through its full travel with the connector visible and watch for the harness binding or pulling. If the loop still reads open at the seat connector, the inflator or the in-seat wiring is the problem, and we carry genuine OEM seat side airbags for Nissan and Infiniti. Related codes: B1121, B1134, 01025.