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.
The driver door ajar switch circuit is reporting an implausible signal. The interior light may stay on or door open warning may be incorrect.
Common causes
- high
Corroded door switch / striker
One of the most commonly reported causes for this code — check this first.
Typical part cost: $40-220
- medium
Wire break in door harness
A plausible cause — test and verify before replacing parts.
Typical part cost: $40-220
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First things to check
- 1Confirm the code with a scan tool and check for additional related codes.
- 2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.
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Related codes
See related trouble codes
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Frequently asked questions
What does B0540 mean?
B0540 means "Driver Door Ajar Switch Circuit". It is a generic OBD-II code that points to a fault in the body.
What are the most common causes of B0540?
corroded door switch / striker; wire break in door harness — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.
Can I keep driving with this code?
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical. Use the Wrenchify app for a full diagnosis specific to your vehicle.
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