C1252Brake booster pump runs too long

• Toyota/Lexus code · ABS / stability control
• Lights a warning lamp

How the car detects it

The pump that keeps the brake booster's accumulator under pressure ran for longer than it should, which means it can't build or hold the pressure. On 2011-2015 Prius and 2007-2011 Camry Hybrid, Toyota links this code, together with C1256 and C1391, to a small internal fluid leak in the brake booster or actuator. Braking still works, but the brake assist may be reduced and the pedal can feel different. If the red brake warning light is on, have the car checked before driving further.

What you may notice

• Brake, ABS and/or VSC warning lights
• Pump running more often or longer than usual

Likely causes

• PossibleInternal leak in the brake booster / actuator
• PossibleBrake booster pump
• RareAccumulator pressure sensor

Sources

• purefjcruiser.com › 0280012.pdf
• static.nhtsa.gov › MC-10109482-9999.pdf · official document
• static.nhtsa.gov › MC-10158575-9999.pdf · official document
• static.nhtsa.gov › MC-11011632-0001.pdf · official document

Backed by an official manufacturer document.

From Obdaryn's Toyota/Lexus pack, exactly as the app shows it, with the public sources above. Guidance only; confirm with a workshop.