OBD-II code · Body
B0540 Driver Door Ajar Switch Circuit
The driver door ajar switch circuit is reporting an implausible signal. The interior light may stay on or door open warning may be incorrect.
Is it safe to drive with B0540?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyCorroded door switch / striker
- PossibleWire break in door harness
Symptoms
- Warning light or symbol related to the affected system
- Comfort or safety function impaired
Repair at a glance
- Difficulty
- Easy
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.4–1.5 h
- Emissions test
- Usually unaffected
- Parts involved
- Driver Door Ajar Switch, Body Control Module
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.