The service engine light comes on with a code P0193 "Fuel Pressure High". The fuel pressure per the monitor is 39.6 PSI (273 KPA) and the bank 2 Long Term Fuel is 4.3 compared to 1.6 for bank 1. The light comes back on within 3 days of clearing codes. It seems to run fine. Any suggestions?

Does the Vehicle start an run ? What engine does it have ? 4.0 or 4.6 L You vehicle has electronic returnless fuel system , Fuel rail pressure sensor , FPDM - fuel pump driver module . The fuel pump driver module controls the fuel by pulse width modulation
Pulsewidthmodulation (PWM) is a powerful technique for controlling analog circuits with a processor's digital outputs. PWM is employed in a wide variety of applications, ranging from measurement and communications to power control and conversion. The PCM - engine computer uses the fuel rail pressure sensor input to send commands to the FPDM .
What code ? P0--- what ?



P0190 - Fuel Rail Pressure (FRP) Sensor Circuit Malfunction Description: The comprehensive component monitor (CCM) monitors the FRP sensor to the powertrain control module (PCM) for VREF voltage. The test fails when the VREF voltage from the PCM drops to a voltage less than a minimum calibrated value. Possible Causes:

• VREF open in harness.
• VREF open in sensor.
• Vacuum leaks.

Diagnostic Aids: Verify a VREF voltage between 4 and 6 volts. Application Key On Engine Off Key On Engine Running Continuous Memory Fuel rail pressure temperature (FRPT) sensor - GO to DD26 GO to DD26 Fuel rail pressure (FRP) sensor only - - GO to DD1 Fuel rail pressure (FRP) and fuel rail temperature (FRT) sensors - - GO to DD1


P0191 - Fuel Rail Pressure (FRP) Sensor Circuit Performance Description: The comprehensive component monitor (CCM) checks the FRP for acceptable fuel pressure. The test fails when the fuel pressure falls below or exceeds a minimum/maximum calibrated value for a calibrated period of time. Possible Causes:

• High fuel pressure.
• Low fuel pressure.
• Damaged FRP sensor.
• Excessive resistance in the circuit.
• Vacuum leaks.
• Low or no fuel.

Diagnostic Aids: A FRP PID value during key on engine running (KOER) of 138 kPa (20 psi) to 413 kPa (60 psi) is acceptable. Application Key On Engine Off Key On Engine Running Continuous Memory Fuel rail pressure temperature (FRPT) sensor GO to DD34 Fuel rail pressure (FRP) sensor only GO to DD9 Fuel rail pressure (FRP) and fuel rail temperature (FRT) sensors GO to DD9


P0192 - Fuel Rail Pressure (FRP) Sensor Circuit Low Input Description: The comprehensive component monitor (CCM) monitors the FRP sensor circuit to the powertrain control module (PCM) for low voltage. If voltage falls below a calibrated limit for a calibrated amount of time during testing, the test fails. Possible Causes:

• FRP signal shorted to SIG RTN or PWR GND.
• Damaged FRP sensor.

Diagnostic Aids: A FRP PID value during the key on engine off (KOEO) or key on engine running (KOER) less than 0.3 volt indicates a hard fault. Application Key On Engine Off Key On Engine Running Continuous Memory Fuel rail pressure temperature (FRPT) sensor GO to DD26 GO to DD26 GO to DD39 Fuel rail pressure (FRP) sensor only GO to DD1 GO to DD1 GO to DD14 Fuel rail pressure (FRP) and fuel rail temperature (FRT) sensors GO to DD1 GO to DD1 GO to DD14


P0193 - Fuel Rail Pressure (FRP) Sensor Circuit High Input Description: The comprehensive component monitor (CCM) monitors the FRP sensor circuit to the powertrain control module (PCM) for high voltage. If voltage exceeds a calibrated limit for a calibrated amount of time during testing, the test fails. Possible Causes:

• FRP signal shorted to VREF or VPWR.
• FRP signal open.
• Damaged FRP sensor.

Diagnostic Aids: An FRP signal high condition can be caused by any number of conditions, including a short on FRP signal to VREF, a more positive voltage level, an open FRP signal or signal return. The FRP signal line is pulled up by the PCM and VREF at the sensor, and down by the sensor through SIGRTN. Application Key On Engine Off Key On Engine Running Continuous Memory Fuel rail pressure temperature (FRPT) sensor GO to DD26 GO to DD26 GO to DD39 Fuel rail pressure (FRP) sensor only GO to DD1 GO to DD1 GO to DD14 Fuel rail pressure (FRP) and fuel rail temperature (FRT) sensors
P1233 Ford Fuel Pump Driver Module Diagnostics and Repair

FPDM Live

P0191 - Fuel Rail Pressure Sensor Circuit Performance (FRP) The comprehensive component monitor (CCM) monitors the FRP pressure for acceptable fuel pressure. The test fails when the fuel pressure falls below or exceeds a minimum/maximum calibrated value for a calibrated period of time. High fuel pressure.
Low fuel pressure.
Damaged FRP sensor.
Excessive resistance in circuit.
Low or no fuel.
A FRP PID value during KOER of 138 kpa (20 psi) and 413 kpa (60 psi) for gasoline or 586 kpa (85 psi) and 725 kpa (105 psi) for natural gas vehicles (NG) is acceptable. You will have to check these items to find the cause of the code. no short cuts.

You should have a test port on the Fuel Supply rail, use a tool from a local auto parts "Tool Loaner program" where you can borrow tools for free,w/a deposit of course,then follow the steps provided;

MPI Fuel System Pressure Test

The MPI fuel system used in vehicles equipped with a 4.OL engine employs a vacuum balanced pressure regulator. Fuel pressure should be approximately 55-69 kPa (8-10 psi) lower with the vacuum line attached to the regulator than with the vacuum line disconnected. System fuel should be 214 kPa (31 psi) with the vacuum line connected to the regulator and 269 kPa (39 psi) with the vacuum line disconnected. CAUTION: Some fuel may be discharged when connecting fuel gauge to fuel rail.

1. Connect a 0-414 kPa (0-60 psi) fuel pressure gauge to test port pressure fitting on fuel rail (Fig. 7).
2. Remove vacuum line from pressure regulator.
3. Start the vehicle.
4. Note gauge reading. With vacuum line disconnected, fuel pressure should be approximately 269 kPa (39 psi).
5. Connect vacuum line to pressure regulator. Note gauge reading. Fuel pressure should be approximately 214 kPa (31 psi).
6. If fuel pressure is not approximately 55-69 kPa (8-10 psi) higher with vacuum line removed from regulator, inspect pressure regulator vacuum line for leaks, kinks or blockage. CAUTION: Fuel pressure will rise to as much as 655 kPa (95 psi) when the fuel return tine is pinched shut, shut engine down immediately after pinching oft fuel return line.
7. If fuel pressure is low, momentarily pinch shut the hose section of the fuel return line. If fuel pressure remains low, inspect the fuel supply line, fuel filter, and fuel rail inlet for blockage. If fuel pressure rises replace fuel pressure regulator.
8. If fuel pressure is above specifications, inspect the fuel return line for kinks and blockage.

Capacity Test

1. Remove the cap from the pressure test port in the fuel rail.
2. Connect a 0-414 kPa (0-60 psi) fuel pressure gauge to the pressure fitting on the fuel rail (Fig. 7).
3. Start the vehicle. Pressure should be approxi- mately 214 kPa (31 psi) with the vacuum hose connected to the pressure regulator and 269 kPa (39 psi) with the vacuum hose removed from the pressure regulator.
4. If the pressure is not to specification, check the following before replacing the fuel pressure regulator:

• 4a - Inspect the fuel supply and return lines/hoses for kinks or restricting bends
• 4b - Check the fuel pump flow rate. A good fuel pump will deliver at least 1 liter of fuel per minute with the fuel return line pinched off. If the fuel pump does not pump adequately, then inspect the fuel system for a plugged fuel filter or fuel pump inlet filter (sock). Fuel pump flow rate can be done by connecting one end of an old A/C gauge hose to the fuel test port on the fuel rail and inserting the other end of the hose into a container of at least 1 liter capacity. Run the fuel pump by installing a jumper wire into diagnostic connector terminals D1-5 and D1-6. Be sure to pinch off the fuel return line or most of the fuel will be returned to the fuel tank.

the 3.3L engine fuel system operates at 55 psi (379 kPa). With the engine idling and the manifold vacuum applied to the regulator, the system operates at approximately 46 psi (317 kPa). Without vacuum applied to the regulator, the 3.5L engine fuel system operates at 48 psi (331 kPa). With the engine idling and the manifold vacuum applied to the regulator, the system operates at approximately 39 psi (269 kPa).---------------------------------------------------------------------------------
Renault CAN Clip

If you have replaced the sensor, check the wires at the back of the plug. Pull them one at a time, if they stretch it is a broken wire. When you get a high reading code. It is either it's unplugged or a wire is broken.

P0193 FORD - Fuel Rail Pressure Sensor Circuit High Input
Symptoms - Engine Light ON (or Service Engine Soon Warning Light)
- Engine will not start Possible causes - Excessive resistance in the circuit
- Low or no fuel
- Wiring harness connector of the fuel pressure sensor
- Fuel Rail Pressure Sensor
- Fuel Pump

1. Without vacuum applied to the regulator, the 3.3L engine fuel system operates at 55 psi (379 kPa). With the engine idling and the manifold vacuum applied to the regulator, the system operates at approximately 46 psi (317 kPa).
   
2. Without vacuum applied to the regulator, the 3.5L engine fuel system operates at 48 psi (331 kPa). With the engine idling and the manifold vacuum applied to the regulator, the system operates at approximately 39 psi (269 kPa).
   
3. The fuel system pressure varies with the different amounts of manifold vacuum applied to the regulator. If the pressure is NOT correct, record the pressure and remove the gauge.
   

P0193 is "Fuel Rail Pressure Sensor Circuit High Input"
Meaning: Car's computer is reading input voltage from the FRP (Fuel Rail Pressure) sensor as
voltage out of the acceptable range, because the voltage is too above the acceptable range.

assuming you are running gasoline...

check for fuel in the vacuum hose of the FRP sensor after running engine at idle for 2 minutes. if not, check fuel pressure. Check fuel pressure by connecting a fuel pressure gauge to the Schrader
connector on the fuel rail, which you will find under a small (black, usually) plastic protective cap.

If the fuel pressure is indeed too high, your fuel pressure regulator has gone bad.

if fuel pressure is good, check voltage between Sensor connector Vref (Pin#3 LB (light blue)) and
Signal Return (Pin#4 GY/RD (gray/red)), which should be 4.0V-5.5V with key ON.
The acceptable voltage range from the FRP sensor to the car's computer is 4.0-5.5 volts.
What the P0193 code is saying is that the voltage from the FRP sensor is over 5.5 volts,
and therefore it's "High Input."

If voltage from the FRP sensor is bad (out of range high, presumably), then replace the FRP
sensor and reset the OBD-II code.

If the voltage output from the FRP sensor is also good, the car's computer is kaflooey, so
you'd need to replace the car computer (which is costly), so replace the car's computer as a
last resort.

You have an engine control unit, but that is rarely the problem. Is your engine light on? If yes, let me know and I'll send procedures for extracting the trouble codes that may identify the problem.
If no engine light, the first thing I would check is the fuel pressure regulator. Pull the vacuum hose off the regulator and plug it with a golf tee. Start the engine and see if gas comes out the vacuum port on the regulator. Is indicates a busted diaphram. Even if the diaphram is good, I would then borrow a fuel pressure gage and run the tests below to make sure the regulator is working to keep the pressure at 39psi. Let me know if this isn't it or you have more questions.

1. Relieve fuel system pressure.
2. Turn ignition switch OFF and disconnect the negative battery cable.

When disconnecting any fuel system hoses, always place a shop towel to prevent residual fuel from spaying.

1. Disconnect the high pressure hose at the delivery side. Using a fuel pressure gauge and adapter (09353-24000 or equivalent), install the adapter to the delivery pipe.
2. Connect the negative battery cable.
3. Activate the fuel pump, by applying battery voltage to the fuel pump drive terminal. Check that there is no leakage from pressure gauge or connections.
   

Fig. Fig. 12: Fuel pump drive terminal location-Excel

1. Disconnect the vacuum hose from the pressure regulator and plug.

Fig. Fig. 13: Fuel pump drive terminal location-Sonata

1. Operate the engine at idle and check the fuel pressure. Fuel pressure should be 47-50 psi (330-350 kPa).
2. Reconnect the vacuum hose to the pressure regulator. With the engine idling, fuel pressure should be 39 psi (270 kPa).
3. If the specified values are not met, make the necessary repairs, as indicated in the diagnosis chart.
4. Shut the engine OFF. Check that the fuel pressure is maintained at the value indicated in Step 8, for approximately 5 minutes.
5. Relieve the fuel pressure.
6. Remove the fuel pressure gauge and reconnect the high pressure hose, using a new O-ring.
7. Start the engine and check for leaks.

The fuel system is under a constant pressure, even with engine off. before servicing the fuel filter/fuel pressure regulator, the fuel system pressure must be released.
CAUTION The fuel system is under pressure when the engine is running, 58 psi, plus or minus 5 psi. (400 kPa plus or minus 34 kPa). The fuel pump module contains a check valve to maintain some fuel pressure even when the engine is not operating. This will help to start the engine. Before servicing the fuel filter/fuel pressure regulator, the fuel system pressure must be released.

Hope this help.