|Trouble Code||Fault Location||Probable Cause|
|P2293||Fuel pressure regulator 2 - performance problem||Wiring, fuel pressure regulator|
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What Does Code P2293 Mean?
OBD II fault code P2293 is a generic trouble code that is defined as “Fuel Pressure Regulator 2 Performance”, and is set when the PCM (Powertrain Control Module) detects a difference between the desired fuel pressure and the actual fuel pressure that exceeds a specified maximum allowable threshold.
Regardless of whether any give vehicles’ fuel pressure regulator is located on the fuel rail or in the fuel tank, the primary function of the fuel pressure regulator is to maintain the pressure in the fuel system to within a narrow pressure range. This is particularly important in systems in which the fuel pump runs at a steady speed since a sudden demand for fuel could cause the fuel pressure to decrease to below the level where the injectors can atomize the fuel effectively.
However, on return-less fuel systems, the speed of the fuel pump is adapted /controlled by the PCM to alter the fuel pressure to suit the demand for fuel at any given moment. If more fuel is required, the PCM increases pump speed, and when fuel demand decreases, the PCM reduces the pump speed. Nonetheless, in both designs, the volume of fuel that enters the cylinders is determined by the injectors’ pulse width, which is the length of time the injectors are open, as opposed to being determined by the fuel pressure as such.
Therefore, if the fuel system is fully functional, i.e., if the fuel pressure falls within the desired or commanded range, increasing the injectors’ pulse widths to inject more fuel for longer will not affect the total pressure of the fuel in the system in meaningful ways. If, however, the fuel pressure is at or below the desired range at any engine speed, suddenly increasing the injectors’ pulse widths could have the effect of lowering the fuel pressure to below the point where fuel can be injected, which could have potentially dangerous consequences, such as when the vehicle hesitates or even stalls unexpectedly in fast-moving traffic.
Thus, maintaining the specified pressure in the fuel system is not only required to maintain acceptable exhaust emission levels but also to ensure that the engine always performs at its peak. Therefore, if the PCM detects a fault, failure, or malfunction in the fuel pressure regulator’s control system or circuits that prevents it from exercising effective control over the actual pressure in the fuel system via the fuel pressure regulator, it will set code P2293 and illuminate a warning light.
Where is the P2293 sensor located?
The image above shows the location of the fuel pressure regulator on the fuel rail of a 1.8L VW engine as used in the Audi A4. Note though that while the design or appearance of most fuel pressure regulators that are located on fuel rails follow this general pattern, there are nevertheless some design differences between manufacturers and applications. For instance, some regulators are held in place by a clip such as is shown here, while others are retained in place by small bolts or screws. In most cases though, the pressure regulator will be the only sensor on the fuel rail and these devices can, therefore, be easily identified by either a vacuum hose (as shown here) or an electrical connector.
In some designs, the fuel pressure regulator is located in the fuel pump canister in the fuel tank, and in these cases, the fuel pump canister must be removed from the fuel tank to gain access to the fuel pressure regulator.
What are the common causes of code P2293?
The most common causes of code P2293 are much the same across all applications, and could include one or more of the following-
- Excessive fuel pump output as the result of faulty fuel pump control circuits
- Insufficient fuel pump output as the result of a clogged fuel filter or pinched/damaged fuel lines
- Faulty or defective fuel pressure regulator
- Burnt, damaged, shorted, disconnected, or corroded wiring and/or electrical connectors
- Split, dislodged, or perforated vacuum hoses in designs where the pressure regulator is vacuum operated
What are the symptoms of code P2293?
Most common symptoms of code P2293 are largely similar across all applications, although the severity of one or more symptoms may vary from vehicle to vehicle. Common symptoms could include one or more of the following-
- Illuminated MIL (CHECK ENGINE) warning light
- One or more codes relating to oxygen sensors and/or fuel trims may be present along with code P2293
- Vehicle may be hard to start under some conditions, or may not start at all depending on the vehicles and the nature of the problem
- Varying degrees of power loss may be present, depending on both the vehicle and the exact nature of the problem
- Fuel consumption may increase