P050F
Brake Assist Vacuum Too Low
The ECU monitors the vacuum supplied to the brake booster (either via a dedicated sensor or via intake manifold pressure). The level has dropped below the calibrated threshold; brake-pedal feel will be hard, and an electric vacuum pump may be commanded to restore vacuum.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Vacuum leak in booster line or check valveCommon
- Electric vacuum pump weakPossible
Parts involved
- Brake Booster
- Vacuum Pump
- Vacuum Check Valve
P050F is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.