C0266
Active Brake Booster
The brake control module has detected a fault in the active (electric or vacuum-controlled) brake booster. Active boosters are used by emergency brake assist and adaptive cruise control to autonomously build brake pressure.
The brake control module has detected a fault in the active (electric or vacuum-controlled) brake booster. Active boosters are used by emergency brake assist and adaptive cruise control to autonomously build brake pressure.
Common causes
- high
Active booster motor or solenoid failed
One of the most commonly reported causes for this code — check this first.
Typical part cost: $440-2750
- medium
Vacuum supply weak (vacuum pump or hose fault)
A plausible cause — test and verify before replacing parts.
Typical part cost: $440-2750
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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 C0266 mean?
C0266 means "Active Brake Booster". It is a generic OBD-II code that points to a fault in the chassis.
What are the most common causes of C0266?
active booster motor or solenoid failed; vacuum supply weak (vacuum pump or hose fault); wiring or connector 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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