What does it mean?
B1808 is a Body (airbags, seat belts, body electronics) fault code. It indicates: Passenger Door Lock/Unlock Switch Circuit Stuck Lock .
Symptoms
- Doors relock themselves seconds after being unlocked
- Lock actuators cycle repeatedly with a clicking noise
- Unlocking from the remote works only briefly
- Possible lockout with the key inside the vehicle
- Battery drain from repeated actuator operation
Likely causes
- Lock contact stuck closed inside the passenger switch pack
- Corrosion inside the switch bridging the lock contact after water intrusion
- Lock signal wire shorted to ground permanently
- Damaged conductors touching each other inside the door hinge boot
- Door trim panel or clip pressing on the switch after reassembly
- Passenger door module input latched active
How to fix it
- Monitor the passenger lock switch status in live data with nothing pressed
- Unplug the passenger switch pack; if the state clears the switch is faulty
- Measure the lock contact resistance at rest, an open reading is correct
- Check the door for water and clear the drain holes
- With both ends disconnected, ohm the lock wire to ground
- Refit the trim carefully to make sure nothing presses on the switch
- Replace the switch pack or repair the short, then verify with a full lock cycle