What does it mean?
B1396 is a Body (airbags, seat belts, body electronics) fault code. It indicates: STPS (Seat Track Position Sensor) - Driver Open or Short to Ground .
Symptoms
- SRS lamp on with a driver seat position circuit code stored
- The scan tool value sits at or near zero and does not respond as the seat is moved
- Airbag deployment force uses its default setting instead of adapting to seat position
- The fault often sets while the seat is being slid, then may drop out again
- Vehicle drives and starts normally
Likely causes
- Sensor signal wire chafed against the driver seat frame or a rail bolt and touching bare metal
- Broken conductor in the under-seat loom, giving an open that reads as a dead low signal
- Wet carpet or a spill in the driver seat connector creating a leakage path to ground
- Loom trapped between the seat pan and the floor when the seat was refitted
- Sensor failed internally with its output stuck low
- Corroded terminal at the sensor or at the restraint module connector
- Airbag control module input fault
How to fix it
- Note the live value; a reading stuck at the bottom of the range supports an open or a short to ground
- Power down the restraint system safely and observe the discharge time before disconnecting anything
- Unplug the sensor and measure the signal wire to body ground; a low reading with the sensor out confirms a shorted harness
- If the wire is not shorted, check it for continuity end to end to find an open
- Inspect the loom where it crosses the seat frame and rail bolts for bare copper and crush damage
- Dry any moisture in the connector and cure the source of the water
- Replace the sensor only after the harness, connector and ground are proven good, then verify the value tracks the seat