OBD-II Code
P0148
Severity
Not yet reviewed
Nobody on our side has assessed this code yet, so we are not going to guess at how serious it is.
Can you drive it
We cannot say
Treat it as unknown until a shop reads it with live data. If the check-engine light is FLASHING, stop driving as soon as it is safe to — that means an active misfire, whatever the code.
Indicative cost (USD)
$250–$4,800
From this code's diagnostic notes. Varies by vehicle, diagnosis, parts, and local labor. This is not a repair quote.
P0148 is a fuel delivery error — the ECM detected that actual fuel rail pressure or commanded injection quantity deviated from the target by more than the manufacturer's threshold for a sustained period (typically 10-30% pressure deviation for 5-10 seconds in modern direct-injection or common-rail diesel systems).
How a shop works this
Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed.
Note every code that is set, not just this one.
Codes that appear together usually narrow the cause faster than any one of them read alone.
Read the freeze frame — the conditions the fault was recorded under.
Cold or warm, idle or load, road speed and engine speed. A fault that only appears cold is a different fault from one that only appears under load, even with the same code on the scanner.
Confirm the fault is current rather than history.
Clear the code and see whether it returns under those same conditions. A code that does not come back may have been logged during a repair, a flat battery, or a bad connection that has since been disturbed.
Then follow the diagnostic notes further down this page, in the order they are written.
They are written in the order a shop works this code, cheapest checks first. Where they name a component, inspect its wiring and connector before replacing it.
If the code comes back after a repair, the underlying fault is still there. That is the point to bring in a scanner with live data and freeze-frame, or a shop that has one.
Common symptoms
- Check engine light
Read the full diagnostic procedureP0148 is a fuel delivery error — the ECM detected that actual fuel rail pressure or commanded injection quantity deviated from the target by more tha…
P0148 is a fuel delivery error — the ECM detected that actual fuel rail pressure or commanded injection quantity deviated from the target by more than the manufacturer's threshold for a sustained period (typically 10-30% pressure deviation for 5-10 seconds in modern direct-injection or common-rail diesel systems). This code is most common on common-rail diesels (Cummins, Duramax, Power Stroke), gasoline direct-injection systems (Ford EcoBoost, GM LTG/LV3, BMW N54/N55, Audi 2.0T TSI), and some Lemon-Squeeze high-pressure-pump returnless gas systems.
Cheapest-first ladder
- Scan live fuel rail pressure (FRP) and commanded FRP — they should track within 5-10% of each other across the operating range; a healthy GDI system holds 1,500-2,200 psi at idle and ramps to 2,500-3,000 psi under load, while a diesel common-rail typically runs 5,000-25,000 psi rail pressure. If actual lags commanded by more than 15%, the high-pressure pump or pressure regulator is failing.
- Check low-pressure (lift pump) fuel pressure with a mechanical gauge — most GDI systems need 55-75 psi on the low side to feed the HPFP; below 45 psi starves the HPFP and triggers P0148.
- Inspect the fuel filter and fuel pump current draw via a low-amp clamp — over 8A on a typical in-tank pump means it's working hard against a clogged filter. The expensive misdiagnosis is replacing the high-pressure fuel pump ($800-$2,400 on most GDI engines) when the actual fault was a $25 fuel filter or a $300 in-tank lift pump.
Vehicle-specific patterns2011-2016 Ford F-150 3.5L EcoBoost throws P0148 from the well-documented HPFP cam-follower wear failure that drops rail pressure under load — Ford is…
- 2011-2016Ford F-150 3.5L EcoBoost throws P0148 from the well-documented HPFP cam-follower wear failure that drops rail pressure under load — Ford issued TSBs and extended-warranty coverage for affected VINs.
- 2007-2013BMW N54 (335i, 535i, 135i) is the canonical P0148 vehicle — HPFP failures are so common that BMW extended the warranty to 10 years/120k miles on affected pumps.
- 2008-2010Dodge RAM 6.7L Cummins diesel sees P0148 from Bosch CP3 high-pressure pump failures after fuel contamination events; the metal debris cycle that follows requires full fuel-system flush plus injectors plus rails.
- 2010-2014Audi/VW 2.0T TSI (EA888) throws P0148 from HPFP cam-follower wear similar to the EcoBoost pattern.
Estimated repair$250 to $4,800.
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