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Test Dd: Fuel Rail Pressure Sensor: Testing

NOTE: Proceed to DTC testing steps listed in FAULT CODE SETTING CONDITION  table of fault code setting condition.
FAULT CODE SETTING CONDITION

Fault Code KOEO KOER Continuous Memory
P0190  DD11  DD11  DD16
P0191  DD17  DD17  DD17
P0192  DD1  DD1  DD16
P0193  DD7  DD7  DD16
P1168 (Natural Gas Only)      DD17
P1169 (Natural Gas Only)      DD17
    NOTE: For additional testing information, see DIAGNOSTIC AIDS .

  1. 1) For KOEO & KOER Only DTC P0192: Verify DTC With FRP PID
    This DTC indicates FRP voltage fell below a minimum calibrated limit and a calibrated minimum amount of time during Comprehensive Component Monitor (CCM). Possible causes for this fault are:
    • FRP Signal Shorted To SIG RTN Or PWR GND
    • FRP Signal Circuit Open (NGV Only)
    • Low Fuel Pressure (NGV Only)
    • Faulty FRP Sensor
    • Faulty PCM

    Ensure vehicle has fuel (natural gas vehicles). Turn ignition switch to ON position. Using scan tool, access FRP PID from PID/DATA MONITOR & RECORD menu. If FRP PID voltage is less than .2 volt, go to next step (natural gas vehicles), or step  3) (all others). If FRP PID voltage is .2 volt or more, concern is intermittent. Go to step  13).

  2. 2) Check Fuel Pressure (Natural Gas Vehicles)

    Start engine. Access FRP PID and monitor fuel pressure. If fuel pressure reading is 80-120 psi (552-827 kPa), go to next step. If fuel pressure reading is not 80-120 psi (552-827 kPa), go to TEST HB, step 1) .
    NOTE: Fuel Rail Pressure (FRP) sensor may also be known as Injection Pressure (IP) sensor.

  3. 3) Generate Opposite Signal

    Turn ignition switch to OFF position. Disconnect FRP sensor connector. Connect a jumper wire between FRP SIGNAL and VREF circuits at FRP sensor harness connector. See Fig 1.
    NOTE: If a scan tool communication concern exists, remove jumper wire and go to step  24).

    Turn ignition switch to ON position. Using scan tool, access FRP V PID from PID/DATA MONITOR & RECORD menu. If FRP V PID voltage is more than 4.6 volts and vehicle is a no start, go to step  5). All others, replace FRP sensor. If FRP V PID voltage is 4.6 volts or less, disconnect jumper wire and go to next step.

  4. 4) Check VREF Voltage To FRP Sensor

    Ensure FRP sensor is disconnected and ignition switch is turned to ON position. Using a DVOM, measure voltage between VREF and SIG RTN circuits at FRP sensor harness connector. See Fig 1 or Fig 2 . If voltage is 4-6 volts, go to next step. If voltage is not 4-6 volts, reconnect sensor and go to TEST C, step  1).

  5. 5) Check FRP Circuit For Open In Harness

    Turn ignition switch to OFF position. Leave FRP sensor disconnected. Disconnect PCM connector(s). Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Using a DVOM, measure resistance of FRP circuit between FRP sensor harness connector and PCM harness connector. See PCM CONNECTOR IDENTIFICATION and Fig 1 or Fig 2 . If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in FRP circuit.

  6. 6) Check FRP Circuit For Short To PWR GND Or SIG RTN

    Using a DVOM, measure resistance between FRP and SIG RTN terminals at PCM harness connector. Also, measure resistance of FRP circuit between negative battery terminal and PCM harness connector terminal. See PCM CONNECTOR IDENTIFICATION and Fig 1 or Fig 2 . If both resistance measurements are more than 10 k/ohms on no starts, go to TEST HB step 19) . All others, replace PCM. If either resistance measurement is 10 k/ohms or less, repair short in affected circuit.
    7. NOTE: For additional testing information, see DIAGNOSTIC AIDS .

  7. 7) For KOEO & KOER Only DTC P0193: Check FRP V PID Value
    This DTC indicates FRP voltage fell below a minimum calibrated limit and a calibrated minimum amount of time during Comprehensive Component Monitor (CCM). Possible causes for this fault are:
    • FRP Signal Shorted To VREF Or VPWR
    • FRP Signal Open (Gasoline Only)
    • Low Fuel Pressure (NGV Only)
    • Faulty FRP Sensor
    • Faulty PCM
    • High Fuel Pressure (Possible Faulty Fuel Pressure Regulator - NGV Only)

    Turn ignition switch to ON position. Using scan tool, access FRP V PID from PID/DATA MONITOR & RECORD menu. FRP V PID voltage should be more than 4.5 volts on natural gas vehicles, and more than 4.8 volts on gasoline vehicles. If FRP V PID voltage is as specified, go to next step (gasoline vehicles), and step  9) (natural gas vehicles). If FRP V PID voltage is not as specified, fault may be intermittent. Go to step  14).

  8. 8) Check FRP Sensor For Fuel Leaks

    Turn ignition switch to OFF position. Remove vacuum hose from FRP sensor. Inspect sensor and vacuum hose for fuel. If any fuel is present, replace FRP sensor. If no fuel is present, go to step  10).
    9. NOTE: In the following test, if natural gas vehicle is not equipped with Schrader valve for fuel pressure gauge installation, use scan tool and access FRP PID from PID/DATA MONITOR & RECORD menu to monitor fuel pressure.

  9. 9) Check Fuel Pressure (Natural Gas Vehicles)
    Start engine. Using scan tool, access FRP V PID from PID/DATA MONITOR & RECORD menu and monitor pressure. If fuel pressure is more than 150 psi (1034 kPa), go to TEST HB, step 1) . If fuel pressure is 150 psi (1034 kPa) or less, go to next step.

  10. 10) Simulate Opposite FRP Signal To PCM

    Turn ignition switch to OFF position. Disconnect FRP sensor connector. Connect jumper wire between FRP and SIG RTN terminals at FRP sensor harness connector. See Fig 1 or Fig 2 . Turn ignition switch to ON position. Using scan tool, access FRP V PID from PID/DATA MONITOR & RECORD menu.
    NOTE: If a scan tool communication concern exists, remove jumper wire and go to step  24).

    If FRP V PID voltage is less than .2 volt, replace FRP sensor. If FRP V PID voltage is .2 volt or more, go to step  12).

    11. NOTE: For additional testing information, see DIAGNOSTIC AIDS .
    NOTE: Before performing this step, check fuel system and repair any external leaks and verify fuel level.

  11. 11) For KOEO & KOER Only DTC P0190: Check VREF Circuit To FRP Sensor
    DTC P0190 indicates VREF voltage from PCM dropped below minimum calibrated voltage during Comprehensive Component Monitor (CCM). Possible causes for this fault are:
    • VREF Open Circuit In Harness
    • VREF Open Circuit In Sensor
    • VREF Open Circuit In PCM

    Disconnect FRP sensor connector. Turn ignition switch to ON position. Using a DVOM, measure voltage between VREF and SIG RTN circuits at FRP sensor harness connector. See Fig 1 or Fig 2 . If voltage is 4-6 volts, go to step  13) (gasoline engines). If voltage is 4-6 volts, go to step  14) (natural gas engines). If voltage is not 4-6 volts, go to next step.

  12. 12) Check FRP, SIG RTN & VREF Circuits For Open In Harness

    Turn ignition switch to OFF position. Disconnect PCM connector(s). Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Using a DVOM, measure resistance of FRP, SIG RTN and VREF circuits between FRP sensor harness connector and PCM harness connector. See PCM CONNECTOR IDENTIFICATION and Fig 1 or Fig 2 . If all resistance measurements are less than 5 ohms, go to next step (gasoline engines). If all resistance measurements are less than 5 ohms, go to step  14) (natural gas engines). If any resistance measurement is 5 ohms or more, repair open in affected circuit.

  13. 13) Check FRP Voltage PID During Fuel Rail Pressure Relief (Gasoline)

    Connect PCM. Connect FRP sensor. Disable fuel delivery system (remove fuel pump fuse). Turn ignition switch to ON position. Access the FRP V PID while cranking the engine to relieve the fuel rail pressure. The FRP voltage will decrease as the fuel rail pressure drops and will stabilize when the fuel rail pressure reaches atmospheric pressure. Note the FRP voltage after it stabilizes at lowest level. If FRP V voltage does not stabilize between 0.3 and 0.7 V, turn ignition switch to OFF position. Replace fuel rail pressure sensor and enable fuel system. If FRP V voltage stabilizes between 0.3 and 0.7 V, proceed as follows:
    • If only Continuous Memory DTC P0190 is present, go to step  16).
    • If DTC P0192 is present, replace PCM.
    • If DTC P0193 is present, go to step  15).

  14. 14) Check FRP Voltage PID During Fuel Rail Pressure Relief (Natural Gas)

    Connect PCM. Connect FRP sensor. Access FRP V PID. Relieve fuel pressure. See FUEL SYSTEM PRESSURE RELEASE under FUEL SYSTEMS in SYSTEM & COMPONENT TESTING - CNG. Crank engine. If FRP V voltage does not stabilize between 0.4 and 0.6 V, turn ignition switch to OFF position. Replace fuel rail pressure sensor and enable fuel system. If FRP V voltage stabilizes between 0.4 and 0.6 V, proceed as follows:
    • If only Continuous Memory DTC P0190 is present, go to step  16).
    • If DTC P0192 is present, replace PCM.
    • If DTC P0193 is present, go to step  15).

  15. 15) Check FRP Circuit For Short To VREF Or VPWR In Harness

    Turn ignition switch to OFF position. Disconnect PCM connector(s). Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Using a DVOM, measure between FRP and VREF, and VPWR circuits at PCM harness connector. See PCM CONNECTOR IDENTIFICATION and Fig 1 or Fig 2 . See PCM VPWR CIRCUIT TERMINAL IDENTIFICATION  table. If both resistance measurements are more than 10 k/ohms, replace PCM. If either resistance measurement is 10 k/ohms or less, repair short in affected circuit.
    PCM VPWR CIRCUIT TERMINAL IDENTIFICATION

    Application PCM Terminal No.
    Models With 104-Pin PCM 71 & 97
    Models With 122-Pin PCM B34, B46 & E9
    Models With 150-Pin PCM A32 & A33, Or B32 & B33
    16. NOTE: For additional testing information, see DIAGNOSTIC AIDS .

  16. 16) For Continuous Memory Only DTC P0190, P0192 & P0193: Check For Intermittent Fault
    Reconnect FRP sensor connector. Turn ignition switch to ON position. Using scan tool, access FRP V PID from PID/DATA MONITOR & RECORD menu. Observe FRP V PID reading for fault while tapping on FRP sensor. Wiggle and bend wiring harness and connector between sensor and PCM. Fault will be indicated by a sudden change in FRP V PID voltage. If fault is indicated, isolate and repair as necessary. If fault is not indicated, symptom is intermittent and cannot be located at this time. Go to TEST Z, step 1) for additional test procedures.
    17. NOTE: For additional testing information, see DIAGNOSTIC AIDS .
    NOTE: On CNG models, if vehicle is a no-start, go to TEST HB, step 1) .

  17. 17) For KOEO, KOER & Continuous Memory DTC P0191, & For Continuous Memory Only P1168 Or P1169 (NGV Only): Check Fuel Pressure
    If DTC P0230, P0231 and/or P0232 are present with DTC P0191, service DTC P0230, P0231 or P0232 before DTC P0191. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . DTC P0191, P1168 or P1169 indicate fuel pressure fell below minimum or exceeded maximum calibrated limit for a calibrated period of time during Comprehensive Component Monitor (CCM). Possible causes for this fault are:
    • High Fuel Pressure
    • Low Fuel Pressure
    • Excessive Resistance In Circuit
    • Faulty FRP Sensor
    • Low Or No Fuel

    Turn ignition switch to ON position. Ensure vehicle has at least 1/8 tank of fuel. Turn ignition switch to OFF position. Release fuel pressure. See FUEL SYSTEM PRESSURE RELEASE procedure under FUEL SYSTEMS in appropriate REMOVAL & INSTALLATION article. Connect pressure gauge to Schrader valve on fuel rail. Turn ignition switch to ON position, with engine OFF. Check fuel pressure. Fuel pressure should be within specification. See FUEL PRESSURE SPECIFICATIONS . If fuel pressure is within specification, go to next step. If fuel pressure is not within specification, go to TEST HB, step 1) (natural gas vehicles), or TEST HC, step 1) (gasoline vehicles).

  18. 18) Check Fuel Pressure With FRP PID

    Connect scan tool to Data Link Connector (DLC). Ensure fuel pressure gauge is still connected. Turn ignition switch to ON position. Using scan tool, access FRP PID from PID/DATA MONITOR & RECORD menu. If FRP PID value is not within 10 psi of fuel pressure gauge measurement, go to next step (natural gas vehicles), or step  20) (gasoline vehicles). If FRP PID value is within 10 psi of fuel pressure gauge measurement, proceed as follows:
    • If DTC P1168 or DTC P1169 are present, perform KEEP ALIVE RANDOM ACCESS MEMORY RESET PROCEDURE under CLEARING CODES under SELF-DIAGNOSTIC SYSTEM. Road test vehicle 3-5 minutes at a steady speed. Stop vehicle and check for Continuous Memory DTCs. If DTC P1168 or DTC P1169 are still present, go to next step.
    • If DTC P0191 is present in Continuous Memory, go to step  15).
    • If any other DTC is present, repeat QUICK TEST .

  19. 19) Check Fuel Rail Solenoid Operation

    Turn ignition switch to ON position. Using scan tool, access OUTPUT TEST MODE. See OUTPUT TEST MODE under ADDITIONAL SYSTEM FUNCTIONS. While observing fuel rail solenoid, cycle output ON and OFF several times. If fuel rail solenoid clicking can be heard or felt, turn ignition switch to OFF position, exit OUTPUT TEST MODE, reconnect solenoid and go to next step. If fuel rail solenoid is not heard or felt clicking, turn ignition switch to OFF position and go to step  23).

  20. 20) Check VREF Voltage To FRP Sensor

    Disconnect FRP sensor connector. Turn ignition switch to ON position. Using a DVOM, measure voltage between VREF and SIG RTN circuits at FRP sensor harness connector. See Fig 1 or Fig 2 . If voltage is 4-6 volts, go to next step. If voltage is not 4-6 volts, go to TEST C, step  1).

  21. 21) Check FRP Circuit For Excessive Resistance

    Turn ignition switch to OFF position. Disconnect PCM connector(s). Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Using a DVOM, measure resistance of FRP, SIG RTN and VREF circuits between FRP sensor harness connector and PCM harness connector. See PCM CONNECTOR IDENTIFICATION and Fig 1 or Fig 2 . If all resistance measurements are less than 5 ohms, go to next step. If any resistance measurement is 5 ohms or more, repair open in affected circuit.

  22. 22) Monitor FRP V PID With Scan Tool

    Turn ignition switch to ON position. Using scan tool, access FRP V PID from PID/DATA MONITOR & RECORD menu. If FRP V PID voltage is less than .2 volt (natural gas vehicles), or more than 4.8 volts (gasoline vehicles), replace FRP sensor. If FRP V PID voltage is not as specified, replace PCM.
    23. NOTE: When ALL ON is selected in OUTPUT TEST MODE, voltage measurement must be made within 7 seconds of activating test mode.

  23. 23) Check FSV PWR Voltage To Fuel Rail Solenoid Shut-Off Valve Harness Connector
    Disconnect fuel rail solenoid connector. Turn ignition switch to ON position. Using scan tool, access OUTPUT TEST MODE. See OUTPUT TEST MODE under ADDITIONAL SYSTEM FUNCTIONS. Select outputs ALL ON. Using a DVOM, measure voltage on FSV VPWR circuit between negative battery terminal and fuel rail solenoid harness connector. See WIRING DIAGRAMS . If voltage is more than 10.5 volts, go to next step. If voltage is 10.5 volts or less, repair open in FSV VPWR circuit.

  24. 24) Check Ground Circuit For Open In Harness

    Using a DVOM, measure resistance of ground circuit between negative battery terminal and fuel rail solenoid harness connector. If resistance is less than 5 ohms, replace fuel rail solenoid shut-off valve. If resistance is 5 ohms or more, repair open in ground circuit.

  25. 25) Check VREF Voltage To FRP Sensor

    Turn ignition switch to OFF Position. Disconnect FRP sensor connector. Turn ignition switch to ON position. Using a DVOM, measure voltage between VREF and SIG RTN circuits at FRP sensor harness connector. If voltage is 4-6 volts, go to next step. If voltage is not 4-6 volts, VREF is out of range. Go to TEST C, step  1).

  26. 26) Check FRP Circuit For Short To SIG RTN, VREF Or PWR GND In Harness

    Turn ignition switch to OFF position. Disconnect scan tool from Data Link Connector (DLC). Disconnect PCM connector(s). Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Using a DVOM, measure resistance between FRP circuit, SIG RTN and VREF circuits at PCM harness connector (both VREF circuits on 150-pin PCM), and negative battery terminal. See PCM CONNECTOR IDENTIFICATION and Fig 1 or Fig 2 . See WIRING DIAGRAMS . If all resistance measurements are more than 10 k/ohms, replace PCM. If any resistance measurement is 10 k/ohms or less, repair short in affected circuit.
Fig 1: Identifying Fuel Rail Pressure Sensor Circuits & Connector Terminals (Natural Gas Vehicles)
G00013253Courtesy of FORD MOTOR CO.
Fig 2: Identifying Fuel Rail Pressure Sensor Circuits & Connector Terminals (Gasoline Vehicles)
G00152731Courtesy of FORD MOTOR CO.
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