What does it mean?
B2435 is a Body (airbags, seat belts, body electronics) fault code. It indicates: Driver Seat Back Heater Sensor Circuit .
Symptoms
- Seat belt reminder chime and lamp stay on with the belt fastened
- The reminder never activates when the belt is unfastened
- The airbag warning lamp is lit alongside the reminder
- The buckle latches normally by feel but the vehicle does not recognise it
- The fault comes and goes as the seat is slid forward and back
Likely causes
- Worn or contaminated contacts inside the driver seat belt buckle switch
- Drink or debris spilled into the buckle housing raising contact resistance
- Damaged or stretched buckle pigtail where it flexes as the seat is moved
- Loose or corroded connector under the seat, a common problem after seat cleaning or carpet work
- Incorrect buckle assembly fitted with a resistance value the module does not recognise
- Wiring under the seat rail crushed by seat travel or by cargo pushed under the seat
- Faulty input inside the restraints or occupant classification module
How to fix it
- Treat this as a restraints fault and follow the safe handling procedure, disconnecting the battery and waiting the specified time before unplugging anything under the seat
- Read the buckle switch state in live data while fastening and releasing the belt several times
- Inspect the connector under the seat for corrosion, moisture and pins that have backed out of the housing
- Measure the buckle switch resistance in both the latched and unlatched states and compare with the specification
- Move the seat through its full travel while watching the reading to catch an intermittent break in the pigtail
- Clean debris out of the buckle housing where contamination is found
- Replace the buckle assembly with the correct part number when the resistance is out of specification, then clear the code and verify the reminder works properly