B1BAA: Occupant Module Configuration Mismatch

Hardware fault

What B1BAA means

The occupant classification module carries configuration data describing the seat and the restraint package it was built for. Other modules on the vehicle carry their own view of that same setup. When those two descriptions disagree, the system cannot be sure which one is correct, so B1BAA gets stored and the airbag lamp comes on.

This most often follows a parts swap. A module pulled from a similar vehicle can look identical and bolt right in while carrying configuration for a different seat or a different restraint content. Physically the install is fine, and the data behind it is what fails.

Common causes

• A used occupant classification module installed from a vehicle with different equipment
• A new module fitted without being configured to the VIN it now lives in
• A restraint module replaced with a different configuration than the seat module holds
• A seat assembly swapped in from another trim level or model
• Programming interrupted partway through, leaving mismatched configuration data

Crash data or hardware fault?

The code lands under hardware because it describes the module's programmed state rather than a live circuit measurement. Crash data is the category people confuse it with, and that is a permanent record written at deployment that no scan tool can erase. A configuration mismatch is fixable through programming.

Does our reset clear it?

Our mail-in reset clears fault memory and returns a module to a ready condition. It does not write new configuration data to match a different vehicle. If the module came out of a donor car, it needs to be configured for the vehicle it is in now, and that is a programming job done with the right tool.

Which makes throw it

B1BAA appears on Chrysler in our lookup, tied to the occupant classification module on seats using weight based detection.

What to do next

Find out whether the seat, the occupant classification module, or the restraint controller has been replaced, because the answer points straight at the mismatch. Compare part numbers and configuration against what the VIN specifies. Correct the configuration with a capable tool, and if the wrong module is in the car, reach out at 501-988-0611 about a genuine OEM replacement for that VIN. Related codes: B1BA8, B1BBA, 53-FF.