What does it mean?
B1811 is a Body (airbags, seat belts, body electronics) fault code. It indicates: Driver Door Ajar Input Circuit High .
Symptoms
- No door open warning on the cluster when the driver door is opened
- Interior lamp does not come on with the door open
- Alarm does not trigger when the door is opened
- Approach or welcome lighting and one-touch window features stop working
- Central locking behaves as if the vehicle were sealed while a door is open
Likely causes
- Open circuit in the ajar signal wire or in the latch ground return
- Latch connector unplugged, loose or with a corroded terminal
- Broken conductor inside the hinge boot that separates when the door swings
- Ajar switch inside the latch worn out and no longer making contact
- Signal wire shorted to battery voltage after an accessory installation
- Module input stage failure holding the line high
How to fix it
- Watch the ajar status on the scan tool while opening and closing the door
- Jumper the latch connector pin to ground and see whether the status changes
- If the status changes with a jumper, the switch inside the latch is faulty
- If it does not, continuity test the signal wire and the ground return through the boot
- Check the latch connector for pushed-out or green terminals
- Measure whether battery voltage is present on the signal wire with the module unplugged
- Replace the door latch assembly or repair the harness, module last