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.
Medium severity. Can I keep driving?If the car is running normally, drive in moderation to a repair shop. If it loses power or another warning appears, do not continue.
Symptoms
- Engine or brake warning lamp on
- Harder brake pedal at low speed or after several stops
- Start-stop function disabled
Most likely causes
- Faulty pump relay, blown fuse or poor relay contact
- False entry after a long engine crank while the pump is unpowered
- Open wire or loose connector between module, relay and pump
- Failed electric vacuum pump
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
- It affects emissions.
What each character of P258A means
- P: Powertrain: engine and transmission
- 2: Generic code: same on every make
- 5: Speed and idle
- 8A: Specific fault in that system
Frequently asked questions
Can I keep driving with code P258A?
If the car is running normally, drive in moderation to a repair shop. If it loses power or another warning appears, do not continue.
What causes code P258A?
The most common causes are: faulty pump relay, blown fuse or poor relay contact; false entry after a long engine crank while the pump is unpowered; open wire or loose connector between module, relay and pump.
Related codes
- P258BVacuum Pump Control Circuit A Range/Performance
- P258CVacuum Pump Control Circuit A Low
- P258DVacuum Pump Control Circuit A High
- P25EEVacuum Pump Control Circuit B/Open
- P050FBrake Assist Vacuum Too Low
Sources
- fordservicecontent.com: OBDSM1901 HEV
- static.nhtsa.gov: MC 10226008 9999
- law.cornell.edu: 13 CCR 1968.2
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.