B1145: Right Curtain Airbag Circuit Open

Circuit fault

What B1145 means

Curtain airbags run the length of the cabin, tucked behind the headliner and the pillar trim. Their firing loop travels up a pillar to reach the inflator. When the control unit measures that loop and finds no continuity, it stores B1145 and disables the system, because it has no way to guarantee the curtain would fire in a rollover or side hit.

The pillar is where these circuits usually break. Headliner work, pillar trim removal, roof rack installation, and windshield replacement all put hands near the curtain connector. Squeezing trim back into place with the connector hanging loose is enough to pull a pin. The module sees the result as an open loop and does not care how it happened.

Common causes

• Curtain airbag connector left disconnected after headliner or pillar trim removal
• A wire pinched behind a pillar trim clip during reassembly
• Water running down from a roof leak or windshield seal into the pillar connector
• An inflator with an open squib inside the curtain module
• Harness damage from roof or quarter panel repair work

Crash data or hardware fault?

Everything about B1145 is live. The control unit measures the curtain loop each time the system arms, so the code reflects the circuit's condition at this moment rather than a past event. Stored crash data is written once during a deployment and stays locked in the module regardless of how many times the codes get cleared.

Does our reset clear it?

A mail-in reset erases what the module has stored, including crash data from a deployment, but it does not reconnect an open curtain circuit. Clearing B1145 while the loop is still open gets you the same code back. Repair the connector or the harness first, then send the module in if it also holds deployment data from a crash.

Which makes throw it

Infiniti and Nissan both use B1145 for the right curtain loop. The routing up the right side pillars is close enough between the two that the same inspection order works on either.

What to do next

Take the right side pillar trim off and find the curtain connector before doing anything with a meter, because a hanging or half seated connector is what this code usually turns out to be. Check for water staining on the pillar foam while you are in there. If the connector is solid and the loop still reads open, the curtain inflator is the failed part, and we stock genuine OEM curtain airbags for these vehicles. Related codes: B1134, B1150, B1038.