What does it mean?
B1810 is a Body (airbags, seat belts, body electronics) fault code. It indicates: Driver Door Ajar Input Circuit Low .
Symptoms
- Dash shows a door open warning with all doors firmly shut
- Interior lamps stay on and the battery goes flat overnight
- Alarm will not arm, or triggers on its own
- Door open chime sounds while driving
- Auto-lock, remote start or convenience features are blocked
Likely causes
- Door ajar switch inside the latch stuck closed or internally shorted
- Corrosion inside the latch assembly after water has run down the door
- Ajar signal wire shorted to ground somewhere between the latch and the module
- Broken or chafed conductors inside the door hinge boot
- Latch plunger held in by a bent striker or a sagging hinge
- Module input failure pulling the ajar line low
How to fix it
- Watch the door ajar status on a scan tool with the door open and then closed
- Unplug the door latch connector and see whether the status changes to closed
- Measure the ajar switch resistance at the latch in both positions
- Inspect the latch for corrosion and water, and check the striker alignment
- Test the ajar wire to ground with both ends disconnected
- Flex the hinge boot loom while watching live data to catch an intermittent short
- Replace the door latch assembly, since the switch is usually not serviced separately