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?
- Replacing the fuel tank
- Replacing the fuel pump
- Replacing the fuel filter
- Replacing the fuel injectors
- Replacing the fuel injector pump
- Replacing the fuel pressure regulator
- Replacing a fuel hose or fuel line
- Replacing a fuel pressure sensor
- Repairing or replacing wiring that is associated with the fuel pressure sensor
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.