B2204: Seat Belt Tensioner Circuit

Circuit fault

What B2204 means

A seat belt tensioner fires a small charge that removes slack from the belt at the beginning of a crash. Like an airbag, it has a firing loop the controller tests with a low test current, comparing the resistance it measures to a stored range. B2204 is what the controller writes when that comparison fails.

The definition on file does not name a specific seat position, so the first job is reading freeze frame data or companion codes to learn which tensioner the controller is reporting on. Working the wrong side of the vehicle is the common mistake with a code written this broadly.

Common causes

• A tensioner connector under a seat or behind a pillar trim panel that is unplugged or loose
• Wiring damaged where the harness flexes with seat travel
• Corrosion at the connector from floor moisture or a spill
• A tensioner that has failed internally and reads outside the expected range
• Harness damage from carpet, trim, or seat removal work

Crash data or hardware fault?

B2204 belongs to the circuit group, meaning it follows a measurement the controller takes in real time and clears once that measurement is back in range. Crash data is stored permanently at the moment of deployment and cannot be erased by a scan tool, which is why deployment records and circuit faults get handled differently.

Does our reset clear it?

A module reset does not repair a tensioner circuit. The controller retests the loop on every key cycle, so B2204 comes back until the wiring or the tensioner is fixed. Where the mail-in reset does its job is on a module carrying crash data after a deployment, once the deployed parts have been replaced.

Which makes throw it

B2204 is used by Chrysler, Dodge, Jeep, and Ram, which share the restraint controller that monitors these tensioner circuits.

What to do next

Identify which seat position the code refers to before pulling any trim, using the scan data and any companion codes on the module. Once you know the location, inspect that connector and the harness that moves with the seat. Measure the loop at the tensioner and at the controller to place the fault, and we can supply genuine OEM seat belt assemblies with tensioners when the part is the problem. Related codes: B1CDB, B2205, 01236.