P0088 trouble code definition

P0088 is Fuel Rail/System Pressure - Too High, indicating a fuel delivery system issue.

This code is similar to P0087. P0088 may also be seen with codes that case misfires, lean, and rich conditions.

What the P0088 code means

P0088 is a OBD2 trouble code that tells us there is high fuel pressure found in the fuel system. This high fuel pressure is detected by the fuel pressure sensor located on the fuel rail. Once the high fuel pressure is detected the ECM causes a Check Engine Light to be seen on the dashboard of the vehicle. P0088 then causes the vehicle to go into a failsafe mode until normal fuel pressure is detected.

What causes the P0088 code?

  • Fuel pressure sensor has failed
  • Kicked or restricted fuel supply line
  • Faulty fuel pressure regulator

What are the symptoms of the P0088 code?

  • P0088 will always have a Check Engine Light accompanied with it
  • The vehicle is put into failsafe mode to prevent damage to the vehicle
  • Poor vehicle running
  • Engine misfires
  • Lean and rich conditions
  • Poor fuel mileage
  • Engine potentially dying

How does a mechanic diagnose the P0088 code?

  • Mechanics will begin by installing a scan tool into the DLC port on the vehicle and reading all OBD2 codes.

  • Codes will all have their own freeze frame information associated with the code that tells us what specific conditions the vehicle was under when the code was set.

  • Codes will then be cleared and a road test performed, this road test should be under similar circumstances as the freeze frame data for an accurate result.

  • If the Check Engine Light returns during the test drive a visual inspection will be done for the fuel system.

  • Fuel lines, fuel rail, external fuel filter, and fuel pressure regulator will all be checked. If nothing abnormal is found during the visual inspection, than a mechanical fuel pressure tester will be used to check fuel pressure at the fuel rail.

  • This information will be compared to the readings from the fuel pressure sensor to determine any discrepancies.

Common mistakes when diagnosing the P0088 code

  • Replacing components without testing them is the most common mistake made during P0088 diagnostic.

  • Step by step diagnosis is the easiest way for foolproof answers, not doing so leads to repairs that do not fix the faults and wasted time, effort, and money.

  • P0088 is commonly caused by a kinked fuel line, this is usually due to something hitting the line. The only way to see this is to perform a thorough visual inspection.

How serious is the P0088 code?

P0088 can be a serious code but one that is not seen very commonly. The symptoms listed above make the vehicle unsafe to drive, so you should consult a mechanic as soon as possible before getting back on the road. High fuel pressure may cause the vehicle’s engine to die while running.

What repairs can fix the P0088 code?

Additional comments for consideration regarding the P0088 code

A P0088 code should be taken seriously when it is found, as it could potentially make the vehicle unsafe to drive.

The fuel pressure test kit is a needed tool for accurate diagnosis of P0088. Though scan tools will tell us what the fuel pressure sensor reading is, these may not be accurate if the fuel pressure sensor is faulty. The fuel pressure test port is found on or near the fuel rail and is used to provide an accurate reading to base findings from.

Need help with a P0088 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

This article originally appeared on YourMechanic.com as P0088 OBD-II Trouble Code: Fuel Rail/System Pressure - Too High and was authored by Spencer Clayton.


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