Symptoms of a DTC P2293 may include:
- Poor fuel economy
- Poor acceleration or hesitation
- Other codes may be present, such as lean O2 sensors
- The engine light is on (malfunction indicator)
Potential causes of a P2293 fault code may include:
- Fuel pump output
- Clogged or pinched fuel lines / clogged fuel filter
- Faulty regulator
- Faulty fuel pressure sensor or electrical wiring
Possible Solutions
Fuel Pressure – Fuel pressure can be checked using a mechanical gauge attached to the fuel rail. If the fuel pressure meets factory specifications, there may be an issue with the fuel pressure sensor giving false readings to the PCM/ECM. If no fuel pressure test port is available, fuel pressure can only be checked using an advanced scan tool or by splicing adapter fittings between the fuel lines and the fuel rail.
Fuel Pump – The fuel pump output is determined by the PCM/ECM and may be controlled by an external fuel management computer. The fuel pump can be commanded on the duty cycle on vehicles equipped with returnless fuel systems. An advanced scan tool may be needed to check the output on these types of fuel systems. Test the fuel pump for sufficient power by locating the fuel pump wiring harness. Some vehicles may not be easily accessible to test the fuel pump wiring connections. Check the battery voltage at the positive terminal of the fuel pump using a digital volt-ohmmeter set to the volts scale with the positive lead on the power wire and the negative lead on a known good ground with the key in the on or run position. The fuel pump power wire may only be powered during engine cranking or the vehicle’s running state. The displayed voltage should be close to the actual battery voltage.
If power is insufficient, suspect the fuel pump wiring and trace it back to determine if there is excessive resistance in the wiring, loose wires, or loose/dirty connections. On return-type fuel pumps, the ground can be checked using the DVOM set to the ohms scale with one lead on the ground wire and the other lead on a known good ground. The resistance should be very low. On returnless fuel systems, the trigger wire can be checked using a graphing multimeter or oscilloscope set to the duty cycle scale. Typically, the fuel pump computer’s duty cycle will be double the commanded duty cycle controlled by the PCM/ECM. Using the graphing multimeter or oscilloscope, the positive lead will be connected to the signal wire and the negative lead to a known good ground; it may be necessary to determine which wire is correct using a factory wiring diagram. The actual duty cycle should be about double what the PCM/ECM commands; if the displayed duty cycle is half the amount, the settings on the DVOM may need to be adjusted to match the type of duty cycle being tested.
Fuel Lines – Look for physical damage or bent fuel lines that could cause a restriction in the fuel supply or return lines from the fuel pump. It may be necessary to remove the fuel filter to determine if the fuel filter is clogged and needs to be replaced; it should flow freely in the direction of flow indicated by an arrow on the fuel filter. Some vehicles are not equipped with fuel filters, and the filter is located at the inlet of the fuel pump itself; it will be necessary to remove the fuel pump module to determine if there is a lot of debris in the tank or if the fuel filter has been crushed or pinched, which could also restrict the fuel supply to the pump.
Regulator – On vehicles with a return fuel system, the regulator is usually located on the fuel rail itself. The fuel pressure regulator typically has a vacuum line that will mechanically restrict fuel based on the amount of vacuum provided by the engine. Check for damaged or loose vacuum hoses from the regulator. If the vacuum hose contains fuel inside, the regulator may have an internal leak that would cause a loss of pressure. Using a non-damaging clamp, the hose can be pinched after the fuel pressure regulator – if the fuel pressure is higher with a restriction on the return side of the regulator, the regulator may be at fault. On returnless systems, the fuel pressure regulator may be located inside the gas tank on the fuel pump module, and it may be necessary to replace the fuel pump module as a complete assembly.
Fuel Pressure Sensor – Test the fuel pressure sensor by removing the connector and checking the resistance between the terminals using the DVOM set to the ohms scale with the positive and negative leads on one of the connectors. The resistance should meet factory specifications. Check the fuel pressure sensor’s reference voltage with a factory wiring diagram to determine which wire powers the sensor using the DVOM set to the volts scale with the positive lead on the power wire and the negative lead on a known good ground. The voltage should be about 5 volts, depending on the vehicle.
If the voltage is not within specifications, trace the wiring to determine if there is excessive resistance in the wire supplying the sensor. The signal wire can be checked using the DVOM set to the volts scale with the positive lead connected to the signal wire and the negative lead on a known good ground with the vehicle turned on and running. The displayed voltage should match factory specifications based on the outside temperature and the internal fuel temperature inside the lines. The PCM/ECM converts the voltage to temperature to determine the actual fuel pressure. It may be necessary to check the voltage at the PCM/ECM harness connector to determine if there is a voltage difference. If the voltage at the PCM/ECM is not the same as the voltage displayed at the fuel pressure sensor, there may be excessive resistance in the wiring.
Disconnect the PCM/ECM harness connector and the fuel pressure sensor connector to check for excessive resistance using the DVOM set to the ohms scale with one lead at each end of the harnesses. The resistance should be very low; any excessive resistance may be a fault in the wiring, or there may be a short to power or ground. Look for a short to power by removing the PCM/ECM harness connection with the DVOM set to the volts scale, with the positive lead on the pin for the fuel pressure signal and the negative lead on a known good ground. If the voltage is the same as the reference or higher, there may be a short to power, and the wiring will need to be traced to determine where there is a short. Check for no short to ground by setting the DVOM to the ohms scale with one lead on the signal wire at the PCM/ECM harness connector and the other lead on a known good ground. If there is resistance, there may be a short to ground, and the wiring will need to be traced to determine where there is a short to ground.