B1150: Left Curtain Airbag Circuit Open (Infiniti)

Circuit fault

What B1150 means

Left curtain airbags deploy down over the driver side windows and are packed behind the headliner along the roof rail. The firing wire reaches them through one of the left pillars. B1150 is the module's way of saying that current sent into that loop found nowhere to go, which rules out any chance of a controlled deployment.

Two things make this circuit worth checking carefully. Curtain connectors are usually out of sight, so nobody notices when one gets knocked loose, and the same pillar carries seat belt hardware and trim clips that invite work near the wiring. A code that appeared right after interior work, glass work, or roof work almost always traces back to that job.

Common causes

• Left curtain connector unplugged or not fully locked after headliner, pillar, or visor work
• A wire crushed by a trim clip or a seat belt anchor bolt during reassembly
• Corrosion at the connector from a sunroof drain or windshield leak running down the left pillar
• An open inflator in the curtain module itself
• Harness damage from a prior left side collision repair

Crash data or hardware fault?

B1150 sits in the circuit family because the control unit is taking a live reading. Fix the open and the code goes inactive on its own. That is the opposite of stored crash data, which the module writes permanently after a deployment and holds until the module is reset by someone with the equipment to do it.

Does our reset clear it?

Clearing this code without repairing the loop accomplishes nothing lasting. The module measures the left curtain circuit again within seconds of powering up and sets B1150 right back. Our reset service is for modules that are locked with crash data after a deployment, and it is the right call once the physical repairs on the car are finished.

Which makes throw it

Nissan and Infiniti both report B1150 for the left curtain loop. Whichever badge you are working on, the sequence is the same: pillar trim off, connector inspected, then a resistance check back to the module.

What to do next

Take the left pillar trim off and put eyes on the curtain connector first. Half of these codes end there. If it is seated and clean, measure the loop at that connector to split the circuit, since a good reading at the airbag side points the fault back toward the module and the harness while a bad one points at the curtain. Genuine OEM left curtain airbags are something we keep in stock. Related codes: B1145, B1177, 01025.