What does it mean?
B1371 is a Body (airbags, seat belts, body electronics) fault code. It indicates: STPS (Seat Track Position Sensor) - Driver instability .
Symptoms
- SRS lamp on, often coming and going rather than staying on
- The fault typically sets while the seat is being adjusted or over rough surfaces
- Airbag deployment force falls back to its fixed default instead of adapting to seat position
- The lamp can stay off for days if the seat is left in one place, then return after a seat adjustment
- No effect on how the vehicle runs
Likely causes
- Sensor loose on its bracket, so the air gap to its target changes as the seat is moved
- Carpet fibres, grit and debris packed around the sensor and the seat rail
- Under-seat loom flexing with every seat adjustment, with broken strands giving a signal that comes and goes
- Spilled drink or damp reaching the seat connector and making the reading wander
- Bent or binding seat rail so the seat never settles in a defined position
- Ageing sensor element with a drifting or noisy output
- Corroded pins at the module-side connector
How to fix it
- Check whether the code is stored as intermittent and look at the conditions captured with it
- Power the restraint system down safely before disconnecting the sensor
- Inspect the sensor mounting, its bracket and its air gap, and clean debris out of the seat rails
- Watch the seat track position value on the scan tool while sliding the seat slowly through its full travel and look for dropouts and jumps
- Wiggle the under-seat loom during that test to see whether the signal reacts
- Repair or replace the flexing loom section, and dry out any moisture in the connector
- Replace the sensor once the wiring and connector have been proven good, then cycle the seat several times to verify