B1CDB: Passenger Occupant Detector, Low

Circuit fault

What B1CDB means

The occupant detector sits in the passenger seat and feeds the restraint system a signal about whether the seat is occupied. The controller powers that circuit and reads what comes back, expecting a value inside a known range. A reading below the range sets B1CDB and leaves the system without a dependable occupancy signal.

Occupancy feeds directly into whether the passenger airbag arms. With the detector circuit out of range, the module cannot confirm the seat state, so it stores the fault and turns the airbag warning lamp on rather than making an arming decision on bad information. On vehicles with a passenger airbag status indicator, that lamp may also stop matching who is in the seat.

Common causes

• The detector connector under the passenger seat loose, corroded, or unplugged
• Seat harness wiring shorted to ground where it flexes with seat travel
• A failed detector element inside the seat cushion
• Liquid soaked into the cushion reaching the detector or its wiring
• Damage from aftermarket seat covers or accessories installed through the cushion

Crash data or hardware fault?

This is a circuit fault, which means the value is being read live and changes with the condition of the wiring. Crash data is stored history instead, written permanently into the module when airbags deploy, and it stays there through every code clear and battery disconnect.

Does our reset clear it?

A reset does not correct a low detector circuit, because the controller reads that same input again on the next key cycle. Repair the wiring or replace the detector, then clear codes on the vehicle and confirm the passenger airbag status indicator behaves correctly. The mail-in reset we offer is for modules holding crash data or a stored internal fault.

Which makes throw it

Chrysler carries B1CDB in our lookup, on vehicles using a passenger occupant detector in the front seat.

What to do next

Check the connector under the passenger seat first and look for signs of liquid that has worked down through the cushion, since spills are a frequent cause on this circuit. Test the detector on its own and then the wiring back to the controller. If the detector element in the cushion has failed, that is a seat component repair, and 501-988-0611 will get you to someone who can source the right OEM part. Related codes: B1C4E, B2204, 93E2.