P258B Brake vacuum pump not performing as the computer expects

P258B electronic vacuum pump performance

P258B in short

P258B means the engine computer sees the electric brake vacuum pump not building or holding vacuum as expected. Causes found in service data are a blown pump fuse, damaged wiring or connector, a vacuum hose fault, or an old computer program. The pump helps your brakes, so have it inspected soon.

The brake booster uses vacuum to make the pedal easy to press. Where the engine cannot supply enough vacuum, an electric pump does the job, and the engine computer monitors how well it works. P258B is set when that performance check fails.

FCA's bulletin pairs it with ABS code C1252-92 (vacuum pump control circuit) and says to check the pump operation, fuse, wiring and connector before replacing the ABS module. A later FCA bulletin says many pumps returned under this code were found with no trouble, so electrical and hose connections come first.

FCA has also listed P258B among codes that a powertrain computer software update can clear, and on the Dodge Hornet the code appeared with a stop/start unavailable message. Chevrolet's HHR set it after an extra brake kit was fitted.

Most likely causes

  1. Blown pump fuse, damaged wiring or loose connector

    Supported by vehicle data
    Why it ranks here
    FCA's bulletin says to check the pump operation, fusing, wiring and connector. Two Pacifica owners report a blown vacuum pump fuse and a melted wire at the pump plug.
    What would change this
    Rises if the pump fuse is open or the connector looks burnt. Falls if the fuse, wiring and connector test fine.

  2. Loose or leaking vacuum hose at the pump or booster

    Supported by vehicle data
    Why it ranks here
    FCA tells dealers to check electrical and vacuum hose connections before replacing the pump, because many returned pumps tested fine.
    What would change this
    Rises if a hose is loose, split or oily at its fitting. Falls if the hoses are sound and hold vacuum.
    How to test the vacuum hoses and intake leaks

  3. Powertrain computer software that needs updating (some models)

    Supported by vehicle data
    Why it ranks here
    FCA lists P258B among codes covered by flash updates for the 2018 Pacifica and 2019 Ram 1500, and says to update if normal diagnostics find nothing.
    What would change this
    Rises if a dealer finds your VIN is covered and the software is old. Falls if it is already current.

  4. Vacuum pump worn out or failing

    Possible — needs testing
    Why it ranks here
    The pump is a listed cause for this code, but FCA reports many pumps replaced for it were later found good, so it is a conclusion after the wiring, fuse and hoses.
    What would change this
    Rises if the pump gets power and ground but does not run or build vacuum. Falls if the pump works when tested directly.

What to test first

Start at step 1. Each result tells you what it means and where to go next.

  1. Read all codes with a scan tool. On Chrysler, Jeep and Ram models look for C1252-92 in the ABS module alongside P258B.

    Low riskTool: OBD-II scan tool with ABS access

    • IfC1252-92 is stored with P258B

      It meansFCA treats this as a vacuum pump system fault; do not replace the ABS module for it.

      Go to step 2

    • IfP258B is the only code

      It meansCheck the pedal feel and then the pump circuit.

      Go to step 2

  2. Note whether the brake pedal feels harder than normal or you hear hissing when braking. If it does, do not drive the vehicle.

    Low risk

    • IfThe pedal is hard or hissing is heard

      It meansBraking assist may be reduced; have it towed to a shop.

      Go to step 3

    • IfThe pedal feels normal

      It meansHave the pump circuit checked soon.

      Go to step 3

  3. Have a shop check the vacuum pump fuse, wiring and connector, then the vacuum hoses, then test the pump itself.

    Best left to a shopTool: multimeter, vacuum gauge

    Warning:Pump and brake booster work affects braking. Do not press the brake pedal repeatedly with the pump disconnected, and avoid driving with the pump circuit open.

Symptoms

  • Check engine light, and on some models the ESC light or stop/start unavailable message
  • Hissing when braking, or a brake pedal that is hard to press Gets more serious: stop and have it checked.

How to fix

This is a safety-critical system, so we explain the code but don't give repair steps. Have it inspected by a qualified technician.

Parts and cost context

  • Vacuum hoses and intake leaks:Check hoses and connections before buying a pump, because FCA reports many pumps returned with no fault found. Labour varies; get a quote.

Labor varies by vehicle and shop; get a quote before you approve a repair.

Compare used part prices on PartPriceGuide

On your vehicle

Chrysler

  • 2017–2020 · Pacifica

    Supported by vehicle data

    FCA bulletin S1805000006 covers the Pacifica, and three 2017 Pacifica owners report P258B with a hard pedal, a blown pump fuse or a melted pump wire. Whether the bulletin is still current is not verified.

  • S1805000006 (chrysler)Status unverified

    ESC light, C1252-92 and/or P258B

    2017–2020pacifica · NHTSA 10173320

    Check the vacuum pump operation, fusing, wiring and connector; do not replace the ABS module for C1252-92.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • 18-001-19 REV BStatus unverified

    PCM software update, includes P258B

    2018pacifica · NHTSA 10162529

    Reprogram the PCM when one of the listed codes is set and normal diagnostics find nothing.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Jeep

  • 2018–2023 · Wrangler

    Supported by vehicle data

    FCA bulletins S1805000006 and 9004433 name the Wrangler. A 2017 Wrangler owner quotes the bulletin: check pump operation, fusing, wiring and connector. Bulletin status is not verified.

  • S1805000006 (jeep)Status unverified

    ESC light, C1252-92 and/or P258B

    2017–2020cherokee, gladiator, wrangler · NHTSA 10173320

    Check the vacuum pump operation, fusing, wiring and connector; do not replace the ABS module for C1252-92.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • 9004433 (jeep)Status unverified

    Brake vacuum pump, P258B

    2018–2023wrangler, grand-cherokee · NHTSA 10242706

    Follow the service-library diagnostics, including electrical and vacuum hose connections, before replacing the pump.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Ram

  • 2019–2023 · 1500

    Supported by vehicle data

    FCA bulletins S1805000006, 9004433 and 18-009-19 name the Ram 1500. Bulletin status is not verified.

  • S1805000006 (ram)Status unverified

    ESC light, C1252-92 and/or P258B

    2019–20201500 · NHTSA 10173320

    Check the vacuum pump operation, fusing, wiring and connector; do not replace the ABS module for C1252-92.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • 9004433 (ram)Status unverified

    Brake vacuum pump, P258B

    2019–20231500, 2500, 3500 · NHTSA 10242706

    Follow the service-library diagnostics, including electrical and vacuum hose connections, before replacing the pump.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • 18-009-19 REV BStatus unverified

    PCM software update, includes P258B

    20191500 · NHTSA 10162544

    Reprogram the PCM when the MIL is on with one of the listed codes.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Chevrolet

  • 2008–2009 · HHR

    Supported by vehicle data

    GM bulletin PIC-5149 links P258B to the OHB brake kit fitted per TSB 09-05-22-001A. Bulletin status is not verified.

  • PIC-5149Status unverified

    P258B after installing the OHB brake kit

    2008–2009hhr · NHTSA 10030747

    After the brake kit is fitted the check engine light and P258B set; diagnostics may point at software or the vacuum pump.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • C1252Hybrid brake booster or actuator fault (Toyota, Lexus) or vacuum pump control circuit (Chrysler, Jeep, Ram)

    Shares causes Supported by vehicle data

    FCA's bulletin pairs C1252-92 in the ABS module with P258B in the engine computer; both point at the vacuum pump system.

All ABS, traction and stability control codes

P258B questions

Is it safe to drive with P258B?

Not if the brake pedal is hard or hissing. The pump helps the brakes, so have it inspected soon, and have the vehicle towed if the pedal feels wrong.

Should I replace the vacuum pump?

Not first. FCA says many pumps returned for this code tested fine; fuse, wiring, connector and hoses are checked before the pump.

Sources and review

  1. FCA bulletin S1805000006, ESC light with C1252-92 and/or P258B (NHTSA 10173320) — FCA US LLC
  2. NHTSA complaint ODI 11151434 — NHTSA Office of Defects Investigation (owner complaint)
  3. NHTSA complaint ODI 11547262 — NHTSA Office of Defects Investigation (owner complaint)
  4. NHTSA complaint ODI 11539006 — NHTSA Office of Defects Investigation (owner complaint)
  5. NHTSA complaint ODI 11545669 — NHTSA Office of Defects Investigation (owner complaint)
  6. P258B trouble code definition — troublecodes.net
  7. FCA bulletin 9004433, brake vacuum pump, DTC P258B (NHTSA 10242706) — FCA US LLC
  8. FCA flash bulletin 18-001-19 Rev B, PCM updates (2018 Pacifica; NHTSA 10162529) — FCA US LLC
  9. FCA flash bulletin 18-009-19 Rev B, PCM updates (2019 Ram 1500; NHTSA 10162544) — FCA US LLC
  10. GM bulletin PIC-5149, P258B after OHB brake kit (2008-2009 HHR; NHTSA 10030747) — General Motors
Last reviewed
Written by
Saurabh K.
Editorial review
Pending
Technician review
Technician review pending

This page explains what a code usually means; it is not a substitute for a professional inspection. How we source and review · Report an error

My Car

Pick your car and code pages will point out notes and bulletins for it. Saved only in this browser.

Fill this in from your VIN

Used once to identify your engine; not stored.