P258AVacuum Pump Control Circuit A/Open
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P258A stands for an open or otherwise faulty control circuit A of an electric vacuum pump, which supplies the brake booster on engines that provide too little manifold vacuum, such as hybrids, downsized turbo petrol engines and diesels. Ford's 2018-2019 hybrid OBD summary assigns it to the brake system module: with the pump relay commanded off, a monitoring line voltage outside 1.3-5.0 V for 100 ms sets the code (legacy brake code C1035). Stellantis case S2209000006 explains that the PCM can log P258A after a crank longer than 2.5 s because the pump is unpowered while cranking; in that case the code may simply be cleared, but a P258B alongside points to the pump itself. P258B to P258D cover performance, low and high faults, P25EE the open fault of circuit B. Braking assist can be reduced.
- What you may notice
- Engine or brake warning lamp on
- Harder brake pedal at low speed or after several stops
- Start-stop function disabled
- Likely causes
- LikelyFaulty pump relay, blown fuse or poor relay contact
- PossibleFalse entry after a long engine crank while the pump is unpowered
- PossibleOpen wire or loose connector between module, relay and pump
- RareFailed electric vacuum pump
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €20 – €700
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.