What does it mean?
B1508 is a Body (airbags, seat belts, body electronics) fault code. It indicates: Seat slide sensor system fault power supply circuit (shortcircuited to power supply) .
Symptoms
- Airbag warning lamp on
- Seat position value in scan data pegged at maximum or clearly out of range
- Occasionally a blown seat circuit fuse or a seat function that stops working
- Hard fault that returns immediately after clearing
Likely causes
- Sensor harness chafed against a powered lead in the seat bundle, such as a seat heater, seat motor or seat memory feed
- Aftermarket seat heater, cooler or accessory wiring spliced into the seat harness
- Water and corrosion inside the under-seat connector bridging a powered pin to the sensor line
- Terminal pushed out of position and contacting an adjacent live pin
- Damaged insulation where the harness passes the seat frame after a seat swap or trim repair
- Internal short inside the seat slide sensor pulling the line high
How to fix it
- Ask about and inspect for aftermarket seat heaters or accessories spliced into the seat harness, and remove them for testing
- Unplug the sensor and check the harness side for voltage present with the ignition on
- Follow the seat harness looking for chafe against powered leads and for melted or hardened insulation
- Inspect the under-seat connector for water damage, corrosion and terminals contacting live pins
- Separate the sensor from the harness to establish whether the short is in the wiring or the component
- Repair or replace the damaged harness section and reroute it clear of powered wiring
- Replace the seat slide sensor if the short is internal, then clear the code and retest through full seat travel