Fuel System (Diesel)

P0087Fuel Rail/System Pressure - Too Low

High RiskDifficulty:Moderate1-4 hours
Is it safe to drive?
Short trips, with care

The car usually goes into limp mode and cuts power. It may stall on the road and not restart, so avoid long trips.

Will it pass inspection?
Risky

Smoke and idle problems on a diesel in limp mode may be recorded as defects at inspection.

01 / 06

What does P0087 mean?

The pump can't deliver the pressure the ECU asks for to the rail. Most of the time the cause is not an expensive part: a clogged diesel filter, air getting into the line from the tank, or excessive return from the injectors. Do a filter and return test before replacing the high-pressure pump.

On common-rail diesels, the ECU compares the value from the rail pressure sensor with the target pressure. If measured pressure stays below target for long, P0087 is stored. Any restriction on the low-pressure side (filter, tank pump, hose) and any leak on the high-pressure side (injector return, pressure regulator) can set this code.

02 / 06

How to fix P0087

Steps are ordered from cheapest to most expensive. If a step doesn't solve it, move to the next one, and don't let a garage replace parts blindly.

  1. 1

    Replace the diesel filter

    DIY

    If it's overdue, this is the first step. Bleed the system after replacement.

  2. 2

    Check the low-pressure line

    DIY

    Air bubbles in the clear hoses to the filter mean air is getting in somewhere. Check clamps and hoses.

  3. 3

    Injector return (leak-off) test

    Pro job

    Measuring tubes are attached to the return hoses to compare each injector's return volume. An injector returning too much drops the pressure.

  4. 4

    Compare requested and actual pressure in live data

    Pro job

    Pressure is read at idle and while cranking. If no pressure builds while cranking, suspect the pump or control valve.

  5. 5

    Test the pressure control valve

    Pro job

    The flow or pressure control valve on the pump is cleaned or replaced.

  6. 6

    High-pressure pump

    Pro job

    If every other step checks out, the pump is measured on a test bench. If the pump has disintegrated there may be metal debris in the system, so the rail and injectors are checked too.

Don't replace these first

  • High-pressure pump
  • All the injectors
  • Rail pressure sensor

These parts are often replaced unnecessarily for P0087. Don't spend money on them before doing the checks above.

03 / 06

P0087 symptoms

  • Limp mode, noticeable loss of power
  • Hard starting or slow to start
  • Misfiring when accelerating
  • Stalling while driving
  • Check engine light

04 / 06

What causes P0087?

  • Clogged diesel filterVery high
  • Excessive injector returnHigh
  • Air ingress or cracked hose in the low-pressure lineMedium
  • Faulty pressure / flow control valveMedium
  • Worn high-pressure pumpLow
  • Faulty rail pressure sensorLow

05 / 06

Which cars commonly get P0087?

06 / 06

Frequently asked questions

What does fault code P0087 mean?

P0087 stands for “Fuel Rail/System Pressure - Too Low”. The pump can't deliver the pressure the ECU asks for to the rail. Most of the time the cause is not an expensive part: a clogged diesel filter, air getting into the line from the tank, or excessive return from the injectors. Do a filter and return test before replacing the high-pressure pump.

Can I drive with code P0087?

Short trips, with care. The car usually goes into limp mode and cuts power. It may stall on the road and not restart, so avoid long trips.

Will a car with code P0087 pass vehicle inspection?

Risky. Smoke and idle problems on a diesel in limp mode may be recorded as defects at inspection.

Does P0087 mean the pump has failed?

Not always. The most common causes are a clogged diesel filter and injector return. Consider replacing the pump only after filter and return tests.

Related codes

P0299P0380P2002