B0850
Left Brake Lamp Circuit
A fault has been detected in the left brake lamp circuit.
A fault has been detected in the left brake lamp circuit.
Common causes
- high
Burnt out brake lamp bulb
One of the most commonly reported causes for this code — check this first.
Typical part cost: $10-110
- medium
Brake light switch fault
A plausible cause — test and verify before replacing parts.
Typical part cost: $10-110
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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 B0850 mean?
B0850 means "Left Brake Lamp Circuit". It is a generic OBD-II code that points to a fault in the body.
What are the most common causes of B0850?
burnt out brake lamp bulb; brake light switch fault — 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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