P0094 code definition

Fuel System Leak - Small Leak Detected

What the P0094 code means

The P0094 code is set in a vehicle’s Powertrain Control Module (PCM) when it detects a small leak in the fuel system. It is most common on vehicles with diesel engines.

What are the causes of the P0094 code?

  • Small leak in the injection pump
  • Small leak in the injectors
  • Small leak in the fuel lines and hoses
  • Small leak in the fuel rail
  • Small leak in the fuel filter
  • Small leak in the fuel tank
  • Fuel pressure decreased by the fuel pump, injector pump, a restriction in the fuel system, or a fuel pressure regulator

What are the symptoms of the P0094 code?

  • Running out of fuel faster than normal
  • Decreased fuel economy
  • Check Engine Light illumination
  • Fuel odors
  • Risk of fire

How does a mechanic diagnose the P0094 code?

  • Inspects the fuel system for leaks

  • Repairs any leaks found

If no leaks are found in the fuel system:

  • Conducts a fuel pressure test

If fuel pressure is lower than manufacturer-specified pressure:

  • Inspects the fuel pump
  • Inspects the injector pump
  • Inspects the fuel pressure regulator

Common mistakes when diagnosing the P0094 code

Checking for leaks and, after not finding any leaks, replacing the fuel pressure regulator. This part is a common cause of this issue, however is is always best to know for sure that a part is faulty by testing it before replacing anything.

How serious is the P0094 code?

The P0094 code is not as serious as a P0093 code, due to the fact that the leak is smaller. However, considering that a fuel leak is still possible, the risk of a fire is also possible, which can become a very serious safety issue and could cause injury to the driver and passengers.

What repairs can fix the P0094 code?

Additional comments regarding the P0094 code

Just because this code says that a “small leak” has been detected in the fuel system does not mean that a leak actually exists. This code is set when the PCM sees a noticeable loss in fuel pressure. If the fuel pressure sensor or its circuitry are damaged, or the fuel pressure regulator, fuel pump, or fuel filter are faulty, this can cause a decrease in fuel pressure and therefore cause a P0094 code.

Need help with a P0094 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 to have this issue resolved.

This article originally appeared on YourMechanic.com as P0094 OBD-II Trouble Code: Fuel System Leak - Small Leak Detected and was authored by Andrew Quinn.


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