Your Vehicle: 2001 Ford Escort ZX2 L4-2.0L DOHC VIN 3
 
Vehicle » Powertrain Management » Computers and Control Systems » Testing and Inspection » Pinpoint Tests » DD: Fuel Rail Pressure (FRP) Sensor - Pinpoint Test  
 
 
  DD: Fuel Rail Pressure (FRP) Sensor - Pinpoint Test  
 

DD: Fuel Rail Pressure (FRP) Sensor

DD: Introduction See: DD: Fuel Rail Pressure (FRP) Sensor - Introduction

DD1 DTC P0192: VERIFY DTC WITH FRP PID

  • Key ON, engine OFF.
  • Verify there is sufficient fuel (NG only).
  • Access FRP PID.

Is the FRP PID voltage less than 0.2 volts?
Yes

  • KEY OFF.For NG vehicles:
  • GO to DD2

.

  • Gasoline:
  • Fault is present, GO to DD3

.

No

  • Fault is intermittent.
  • Gasoline:
  • GO to DD13

.

  • NG:
  • GO to DD14

.

DD2 CHECK FUEL PRESSURE (NATURAL GAS)

  • Install fuel pressure gauge.
  • Key ON engine RUNNING.
  • Obtain a pressure reading.

Is the fuel pressure reading greater than 345 kPa (50 psi)?
Yes

  • Key OFF. GO to DD3

.

No

.

DD3 GENERATE OPPOSITE SIGNAL

Note: Refer to the PCM connector pin numbers in the beginning of this pinpoint test.

  • Disconnect FRP harness connector.
  • Natural Gas Vehicles: Jumper FRP SIG pin to VREF pin at the FRP sensor harness connector.

Note: If any scan tool communication concern exists, remove jumper and GO to DD25.

  • Key ON, engine OFF.
  • Access FRP V PID.

Is the FRP V PID voltage greater than 4.6 volts?
Yes

  • No starts:
  • GO to DD5
  • All others:

REPLACE FRP sensor.
Note: Refer to fuel system WARNING text at the beginning.

No

  • GO to DD4

.

DD4 CHECK VREF VOLTAGE TO FRP SENSOR

  • Measure voltage between VREF and SIG RTN circuits at the FRP sensor harness connector.

Is the voltage between 4.0 and 6.0 volts?
Yes

  • Key OFF. GO to DD5

.

No

.

DD5 CHECK FRP CIRCUIT FOR OPEN IN HARNESS

Note: Refer to the PCM connector pin numbers in the beginning of this pinpoint test.

  • Disconnect PCM.
  • Measure resistance of FRP circuit between PCM harness connector pin and FRP sensor harness connector.

Is the resistance less than 5.0 ohms?
Yes

  • GO to DD6

.

No

  • REPAIR open circuit.

DD6 CHECK FRP CIRCUIT FOR SHORTS TO SIG RTN AND PWR GND IN HARNESS

  • Measure resistance between FRP and SIG RTN circuits at the PCM harness connector.
  • Measure resistance of FRP circuit at the PCM harness connector and battery (-) terminal.

Are both resistances greater than 10K ohms?
Yes

REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) See: Programming and Relearning\Flash Electrically Eraseable Programmable Read Only Memory - Flash EEPROM).

No

  • REPAIR short circuit.

DD7 DTC P0193: CHECK FUEL PRESSURE PID VALUE

  • Key ON.
  • Access FRP V PID.

Is the FRP voltage PID greater than 4.5 volts for NG and 4.8 volts for all others?
Yes

  • Key OFF.
  • Gasoline:
  • GO to DD8

.

  • NG:
  • GO to DD9

.

No

  • Fault is intermittent. GO to DD15

.

DD8 CHECK FUEL RAIL PRESSURE SENSOR FOR FUEL LEAKS

  • Remove vacuum hose from fuel rail pressure sensor.
  • Inspect sensor and hose for fuel.

Is fuel present?
Yes

  • REPLACE FRP sensor.

Note: Refer to fuel system WARNING text at the beginning.

No

  • GO to DD10

.

DD9 CHECK FUEL PRESSURE (NATURAL GAS)

  • Install fuel pressure gauge.
  • Key ON, engine RUNNING.
  • Obtain a pressure reading.

Is the fuel pressure reading greater than 1034 kPa (150 psi)?
Yes

.

No

  • Key OFF. GO to DD10

.

DD10 ATTEMPT TO INDUCE OPPOSITE FRP SIGNAL

Note: Refer to the PCM connector pin numbers in the beginning of this pinpoint test.

  • Disconnect FRP sensor.
  • Jumper FRP pin to SIG RTN pin at the FRP sensor harness connector.
  • Key ON, engine OFF.
  • Access FRP V PID.

Note: If any scan tool communication concern exists, remove jumper and GO to DD25.
Is the FRP V PID voltage less than 0.2 volt?
Yes

  • Key OFF. REPLACE FRP sensor.

Note: Refer to fuel system WARNING text at the beginning.

No

  • Key OFF. GO to DD12

.

DD11 DTC P0190: CHECK VREF TO FRP SENSOR

Note: Before proceeding to the following test step, a complete inspection of the fuel system for external leaks must be completed. Repair any leaks before continuing. Verify fuel level before beginning test steps.

  • Key ON, engine OFF.
  • Measure voltage between VREF and SIG RTN circuits at the FRP sensor harness connector.

Is the voltage between 4.0 and 6.0 volts?
Yes

  • Key OFF.
  • Gasoline:
  • GO to DD13

.

  • NG:
  • GO to DD14

.

No

  • Key OFF. GO to DD12

.

DD12 CHECK FRP, SIG RTN AND VREF CIRCUITS FOR OPEN IN HARNESS

  • Disconnect PCM.
  • Measure resistance of FRP circuit between PCM pin and FRP sensor harness connector.

-

  • Measure resistance of SIG RTN circuit between PCM harness connector pin and FRP sensor harness connector.
  • Measure resistance of VREF circuit between PCM harness connector pin and FRP sensor harness connector.

Is each resistance less than 5.0 ohms?
Yes

  • Gasoline:
  • GO to DD13

.

  • NG:
  • GO to DD14

.

No

  • REPAIR open circuit.

DD13 CHECK FRP VOLTAGE PID DURING FUEL RAIL PRESSURE RELIEF (GASOLINE)

  • Disable inertia fuel shutoff switch.
  • Connect PCM.
  • Connect FRP sensor.
  • Key ON.
  • Access the FRP V PID while cranking the engine to relieve the fuel rail pressure. FRP voltage will decrease as the fuel rail pressure drops and will stabilize when the fuel rail pressure reaches atmospheric pressure.
  • Monitor FRP voltage level.

After FRP voltage PID stabilizes is voltage between 0.3 and 0.7 volts DC?
Yes

  • For continuous memory DTC P0190 only:
  • GO to DD16

.

No

  • DTC P0193:
  • GO to DD15

.

  • Key OFF. REPLACE FRP sensor.

Note: Refer to fuel system WARNING text at the beginning.

DD14 CHECK FRP VOLTAGE PID AFTER FUEL RAIL PRESSURE RELIEF (NATURAL GAS)

  • Connect PCM.
  • Connect FRP sensor.
  • Key ON engine running.
  • Access the FRP voltage PID and monitor voltage.
  • Disconnect FRP sensor.
  • Disable inertia fuel shutoff switch.

Note: Engine will reduce the fuel pressure then stall.

  • Crank engine for 6 seconds to insure complete fuel pressure relief.
  • Connect FRP sensor.
  • Access FRP voltage PID and monitor voltage.

Is FRP voltage between 0.4 and 0.6 volts DC?
Yes

  • For continuous memory DTC P0190 only:
  • GO to DD16

.

No

  • DTC P0193:
  • GO to DD15

.

  • Key OFF. REPLACE FRP sensor.

Note: Refer to fuel system WARNING text at the beginning.

DD15 CHECK FRP CIRCUIT FOR SHORT TO VREF OR VPWR IN HARNESS

  • Disconnect PCM.
  • Measure resistance between FRP and VPWR circuits at the PCM harness connector.
  • Measure resistance between FRP and VREF circuits at the PCM harness connector.

Are both resistances greater than 10K ohms?
Yes

No

  • REPAIR short circuit.

DD16 PERFORM WIGGLE TEST ON THE FRP SENSOR CIRCUIT WHILE MONITORING FRP PID FOR SUDDEN VALUE CHANGE

  • Access FRP V PID.
  • While monitoring FRP V PID, tap on the FRP sensor; then wiggle the wiring while looking for sudden changes in the PID voltage as an indication of an intermittent fault.

Is a fault indicated?
Yes

  • REPAIR as necessary.

No

.

DD17 KOEO, KOER DTC P0191 AND CONTINUOUS DTCS P0191 P1168 P1169: CHECK FUEL PRESSURE

Note: If DTC(s) P0230, P0231 or P0232 are received along with P0191, it is necessary to address the P0230, P0231 or P0232 before addressing the P0191 DTC. If P0230, P0231 or P0232 are received, refer to Section 4 See: A L L Diagnostic Trouble Codes ( DTC )\Testing and Inspection\Diagnostic Trouble Code Descriptions
Note: For Natural Gas Vehicles, if vehicle is a no-start, GO to HB1 See: HB: Natural Gas Fuel Delivery System - Pinpoint Test.

  • Key ON.
  • Verify there is sufficient fuel (one eighth tank or greater).
  • Key OFF.
  • Fuel pressure gauge connected.
  • Key ON engine OFF.

Note: For fuel pressure specifications, refer to theFuel Delivery System Test Information Chart in the beginning ofHC .
Is the fuel pressure within range for the vehicle being diagnosed?
Yes

  • GO to DD18

.

No

for gasoline or GO to HB1 See: HB: Natural Gas Fuel Delivery System - Pinpoint Test
for NG vehicles.

DD18 CHECK FUEL PRESSURE WITH FRP PID

  • Connect scan tool.
  • Install fuel pressure gauge.
  • Key ON.
  • Access FRP PID.

Is the FRP pressure reading within 10 psig of the fuel pressure gauge reading?
Yes

  • For DTCS P1168 or P1169:

Clear the DTCs. DRIVE vehicle 3-5 minutes at a steady speed state.
CHECK for Continuous Memory DTC P1168 or P1169. If P1168 or P1169 is
displayed, GO to DD19
.

  • For DTC P0191 in Continuous Memory only:

GO to DD16
.

  • All others:

RERUN Quick Test.

No

  • NG:
  • GO to DD19

.

  • Gasoline:
  • GO to DD20

.

DD19 VERIFY FUEL RAIL SOLENOID SHUT-OFF VALVE OPERATES

  • Key ON.
  • Access and enter the Output Test Mode.
  • Cycle output ON and then OFF several times.

Is a click felt or heard from the fuel rail solenoid shut-off valve?
Yes

  • Key OFF. EXIT Output Test Mode. RECONNECT solenoid valve. GO to DD20

.

No

  • Key OFF. GO to DD23

.

DD20 CHECK VREF VOLTAGE TO FRP SENSOR

  • Disconnect FRP sensor.
  • Key ON, engine OFF.
  • Measure voltage between VREF and SIG RTN circuits at the FRP sensor harness connector.

Is the voltage reading between 4.0 and 6.0 volts?
Yes

  • Key OFF. GO to DD21

.

No

.

DD21 CHECK FRP CIRCUIT RESISTANCE

Note: Refer to the PCM connector pin numbers at the beginning of this pinpoint test.

  • Disconnect PCM.
  • Measure resistance of FRP circuit between PCM harness connector pin and the FRP sensor harness connector.
  • Measure resistance of SIG RTN circuit between PCM harness connector pin and FRP sensor harness connector.
  • Measure resistance of VREF circuit between PCM harness connector pin and FRP sensor harness connector.

Is each resistance less than 5.0 ohms?
Yes

  • GO to DD22

.

No

  • REPAIR as necessary.

DD22 MONITOR FRP V PID WITH SCAN TOOL

  • Connect PCM.
  • Key ON, engine OFF.
  • Access FRP V PID.

Is the FRP V PID value less than 0.2 volt for NG, and greater than 4.8 volts for all others?
Yes

  • REPLACE FRP sensor.

Note: Refer to fuel system WARNING text at the beginning.

No

DD23 CHECK FSV PWR VOLTAGE TO FUEL RAIL SOLENOID SHUT-OFF VALVE HARNESS CONNECTOR

  • Disconnect the fuel rail solenoid shut-off valve at the harness connector.
  • Key ON.
  • Access and enter Output Test Mode on the scan tool.
  • Select: ALL ON.

Note: Measurement must be made within 7 seconds of activating test mode.

  • Measure voltage between the FSV PWR circuit at the fuel rail solenoid shut-off valve harness connector and battery negative post.

Is the voltage reading greater than 10.5 volts?
Yes

  • GO to DD24

.

No

  • Key OFF. REPAIR open circuit.

DD24 CHECK GROUND CIRCUIT FOR OPEN IN HARNESS

  • Measure resistance between the ground circuit at the fuel rail solenoid shut-off valve harness connector and battery negative post.

Is resistance less than 5.0 ohms?
Yes

Note: Refer to fuel system WARNING text at the beginning.

No

  • REPAIR open circuit.

DD25 CHECK VREF VOLTAGE TO FRP SENSOR

  • Disconnect FRP sensor.
  • Key ON, engine OFF.
  • Measure voltage between VREF and SIG RTN circuits at the FRP harness connector.

Is the voltage between 4.0 and 6.0 volts?
Yes

  • Key OFF. GO to DD26

.

No

.

DD26 CHECK FRP CIRCUIT FOR SHORT TO SIG RTN, VREF, OR PWR GND IN HARNESS

Note: Refer to the PCM connector pin numbers in the beginning of this pinpoint test.

  • Disconnect PCM.
  • Disconnect scan tool from DLC.
  • FRP disconnected.
  • Measure resistance between FRP and SIG RTN circuits at the PCM harness connector.
  • Measure resistance between FRP and VREF circuits at the PCM harness connector.
  • Measure resistance between FRP circuit at the PCM harness connector and battery (-) terminal.

Is the resistance greater than 10K ohms?
Yes

No

  • REPAIR short circuit.