B1C4E: Passenger Buckle Tensioner, Open

Circuit fault

What B1C4E means

Open is the most definite of the three buckle tensioner faults. Instead of a reading that is too low or too high, the controller sees no complete path, which is what it would see with the connector unplugged or a wire broken clean through. Since nothing can fire through a broken circuit, the controller disables the system and lights the lamp.

The buckle tensioner connector under the passenger seat is the first suspect on nearly every one of these. Seats get removed for carpet work, interior cleaning, and trim repair, and the SRS connector underneath is easy to leave hanging. The code sets the moment the system runs its next check, which is why an airbag light appearing right after interior work points straight back at that connector.

Common causes

• The buckle tensioner connector left unplugged after seat or carpet work
• A wire broken at a flex point in the seat harness
• A terminal pushed out of the connector so it never contacts
• Corrosion advanced far enough to break continuity entirely
• An internally open tensioner in the buckle assembly

Crash data or hardware fault?

Circuit codes like B1C4E follow a live measurement, so plugging the connector back in restores a normal reading on the next check. Stored crash data is the opposite. It is written at the moment of deployment, stays permanently in module memory, and cannot be removed with a scan tool.

Does our reset clear it?

Clearing the module does not reconnect an open loop. Until the wiring, connector, or tensioner is repaired, B1C4E returns on the next key cycle. Fix the vehicle side first. Our mail-in reset is for modules holding crash data from a deployment or a stored internal hardware fault, which are separate conditions.

Which makes throw it

B1C4E is listed under Chrysler in our lookup, on the first row passenger buckle tensioner circuit.

What to do next

Reach under the passenger seat and confirm the tensioner connector is plugged in and latched, because that one check resolves a surprising share of these. If it is connected, check continuity from the controller connector through to the buckle while flexing the harness. A buckle that reads open with good wiring needs to be replaced, and we stock genuine OEM seat belt buckle assemblies. Related codes: B1C4D, B1CDB, B1901.