What does it mean?
B1289 is a Body (airbags, seat belts, body electronics) fault code. It indicates: Passenger Seat ECU Communication Stop .
Symptoms
- Airbag or occupant classification warning lamp lit, the passenger airbag may be switched off
- Passenger seat heating, memory or power adjustment stops responding
- Scan tool cannot establish communication with the passenger seat module
- Other modules store companion lost-communication codes
- Passenger seat belt reminder behaves incorrectly
Likely causes
- Blown fuse or lost power feed at the passenger seat module
- Broken wires in the under-seat loom that flexes every time the seat is slid forward and back
- Connector under the seat left unplugged or only partly seated after cleaning, seat removal or trim work
- Corrosion in the under-seat connector from spilled liquid or a wet carpet
- Damage to the bus wiring between the seat module and the gateway
- Internal failure of the seat control module
- Replacement module never coded or configured to the vehicle
How to fix it
- Run a full system scan and note every module that also reports lost communication, that pattern shows whether one node or the bus is at fault
- Check the fuse feeding the seat module, then measure supply voltage and ground at its connector
- Slide the seat fully forward and back while inspecting the loom for stretched, pinched or broken wires
- Reseat every connector under the seat and look for corrosion, bent pins or a released lock
- Measure bus resistance and check the seat module branch for an open or a short
- With power, ground and bus proven good, replace the seat module and code it to the vehicle
- Clear codes and confirm the module reports on the bus with the ignition on