B0100

Driver Door Lock Cylinder Switch Circuit

Moderate severity

The body control module has detected a fault in the driver door lock cylinder switch circuit. This switch detects key rotation in the door lock and is used for keyless functions and the alarm system.

Common causes

Lock cylinder switch failed
One of the most commonly reported causes for this code — check this first.
high
Typical part cost: $60-330
Door harness broken in door hinge area
A plausible cause — test and verify before replacing parts.
medium
Typical part cost: $60-330
See all causes + fix costs
Create a free Wrenchify account to unlock the rest for B0100.
Unlock causes
Free forever · No credit card

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.

Get the full step-by-step diagnosis

Create a free Wrenchify account to unlock the rest for B0100.

Unlock diagnosis

Free forever · No credit card

Related codes

See related trouble codes

Create a free Wrenchify account to unlock the rest for B0100.

Unlock related codes

Free forever · No credit card

Frequently asked questions

What does B0100 mean?

B0100 means "Driver Door Lock Cylinder Switch Circuit". It is a generic OBD-II code that points to a fault in the body.

What are the most common causes of B0100?

lock cylinder switch failed; door harness broken in door hinge area — 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.

Get the full B0100 diagnosis for your vehicle

Year, make, model + step-by-step repair help — free plan included.

Diagnose B0100