Powertrain, generic (extended)

P258B Vacuum Pump Control Circuit A Range/Performance

Check engine lightOn

EmissionsRelevant

Drive cycleNot required

Limp modeNo

P258B is the range/performance code for control circuit A of the vacuum pump: the pump is commanded, but its monitoring feedback or the vacuum it produces does not fit. Ford's 2018-2019 hybrid OBD summary sets it from the brake module when the monitoring line sits outside 1.3-5.0 V with the relay off, or below 250 mV for 1 s with the relay on. FCA case S1805000006 for 2017-2020 Pacifica, Cherokee, Wrangler, Gladiator and Ram 1500 links P258B, often with ABS code C1252, to pumps that cannot keep enough vacuum and asks for checks of fuses, terminals, hoses and check valves plus a PCM update from 2019. Audi's Q3 bulletin 2072305 (2021-2024) traces P258B00 to a blown pump fuse after the ABS connector had been unplugged while the engine was running. The brake pedal may feel hard.

Likely causes

Worn or failed electric vacuum pump

Leaking hose or check valve that makes the pump run too long

Blown pump fuse, spread terminals or poor ground

Outdated engine software controlling pump duty cycle

Symptoms

Engine, brake or stability warning lamp on
Hard brake pedal, less brake assist
Start-stop fault message

Repair estimate

DifficultyMediumWorkshop job

Parts and labour€20–900

Time0.3–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

vacuum pumpvacuum lines

Related codes

P258A P258C P258D P25EF P0556

References: fordservicecontent.com, static.nhtsa.gov, static.nhtsa.gov.