Lincoln Blackwood, Ford F-Series Pick-ups, Lincoln Mark LT 2001-2006

Injection Control Pressure (ICP) Sensor

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Operation



The injection control pressure sensor (ICP) is a variable capacitance sensor that when supplied with a 5-volt reference signal from the PCM, produces a linear analog voltage signal that indicates oil pressure in the high pressure oil pump on the 7.3L DIT diesel engine. The ICP sensor provides a feedback signal to indicate high oil pressure so that the PCM can command the correct injector timing, pulse width and injection control pressure for proper fuel delivery at all speed and load conditions.

The FRPT sensor measures the pressure and temperature of the fuel in the fuel rail and sends these signals to the PCM. The sensor uses the intake manifold vacuum as a reference to determine the pressure difference between the fuel rail and the intake manifold. The relationship between fuel pressure and fuel temperature is used to determine the possible presence of fuel vapor in the fuel rail. The temperature sensing portion of the FRPT sensor is a thermistor device in which resistance changes with temperature. The electrical resistance of the thermistor decreases as the temperature increases, and the resistance increases as the temperature decreases. The varying resistance changes the voltage drop across the sensor terminals and provides electrical signals to the PCM corresponding to temperature. Both the pressure and temperature signals are used to control the speed of the fuel pump. The speed of the fuel pump sustains fuel rail pressure which preserves fuel in its liquid state. The dynamic range of the fuel injectors increase because of the higher rail pressure, which allows the injector pulse width to decrease.

Removal & Installation



4.2L Engine


Click image to see an enlarged view

Fig. Fuel Rail Pressure and Temperature Sensor-4.2L Engine


WARNING
Do not smoke or carry lighted tobacco or open flame of any type when working on or near any fuel-related components. Highly flammable mixtures are always present and can be ignited. Failure to follow these instructions may result in personal injury.


WARNING
Fuel in the fuel system remains under high pressure even when the engine is not running. Before working on or disconnecting any of the fuel lines or fuel system components, the fuel system pressure must be relieved. Failure to follow these instructions may result in personal injury.

  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Release the fuel system pressure.
  4.  
  5. Disconnect the battery ground cable.
  6.  
  7. Disconnect the fuel rail pressure and temperature sensor electrical connector.
  8.  
  9. Disconnect the fuel rail pressure and temperature sensor vacuum connector.
  10.  
  11. Remove the bolts and the fuel rail pressure and temperature sensor.
  12.  
  13. Remove and discard the O-ring seal.
  14.  
  15. To install, reverse the removal procedure.
    NOTE
    Install a new O-ring seal and lubricate with clean engine oil prior to installation.

  16.  

4.6L Engine


Click image to see an enlarged view

Fig. Fuel Rail Pressure and Temperature Sensor-4.6L Engine


WARNING
Do not smoke or carry lighted tobacco or open flame of any type when working on or near any fuel-related components. Highly flammable mixtures are always present and can be ignited. Failure to follow these instructions may result in personal injury.


WARNING
Fuel in the fuel system remains under high pressure even when the engine is not running. Before working on or disconnecting any of the fuel lines or fuel system components, the fuel system pressure must be relieved. Failure to follow these instructions may result in personal injury.

  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Release the fuel system pressure.
  4.  
  5. Disconnect the fuel pressure and temperature sensor electrical connector.
  6.  
  7. Disconnect the fuel pressure and temperature sensor vacuum connector.
  8.  
  9. Remove the bolts and the fuel pressure and temperature sensor.
  10.  
  11. Remove and discard the O-ring seal.
  12.  
  13. Install a new O-ring seal and lubricate with clean engine oil prior to installation.
  14.  
  15. To install, reverse the removal procedure.
  16.  

5.4L Engine


Click image to see an enlarged view

Fig. Fuel Rail Pressure and Temperature Sensor-5.4L Engine


WARNING
Do not smoke or carry lighted tobacco or open flame of any type when working on or near any fuel-related components. Highly flammable mixtures are always present and can be ignited. Failure to follow these instructions may result in personal injury.


WARNING
Fuel in the fuel system remains under high pressure even when the engine is not running. Before working on or disconnecting any of the fuel lines or fuel system components, the fuel system pressure must be relieved. Failure to follow these instructions may result in personal injury.

  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Release the fuel system pressure.
  4.  
  5. Disconnect the battery ground cable.
  6.  
  7. Disconnect the fuel rail pressure and temperature sensor electrical connector.
  8.  
  9. Disconnect the fuel rail pressure and temperature sensor vacuum connector.
  10.  
  11. Remove the bolts and the fuel rail pressure and temperature sensor.
  12.  
  13. Remove and discard the O-ring seal.
  14.  
  15. Install a new O-ring seal and lubricate it with clean engine oil.
  16.  
  17. To install, reverse the removal procedure.
  18.  

6.8L Engine


Click image to see an enlarged view

Fig. Fuel Rail Pressure and Temperature Sensor-6.8L Engine


WARNING
Do not smoke or carry lighted tobacco or open flame of any type when working on or near any fuel-related components. Highly flammable mixtures are always present and can be ignited. Failure to follow these instructions may result in personal injury.


WARNING
Fuel in the fuel system remains under high pressure even when the engine is not running. Before working on or disconnecting any of the fuel lines or fuel system components, the fuel system pressure must be relieved. Failure to follow these instructions may result in personal injury.

  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Release the fuel system pressure.
  4.  
  5. Disconnect the battery ground cable.
  6.  
  7. Disconnect the fuel rail pressure and temperature sensor electrical and vacuum connectors.
  8.  
  9. Remove the 2 bolts and the fuel rail pressure and temperature sensor and discard the O-ring seal.
  10.  
  11. Lubricate the new O-ring seal with clean engine oil prior to installation.
  12.  
  13. To install, reverse the removal procedure.
  14.  

Testing





Click image to see an enlarged view

Fig. Fuel Rail Pressure and Temperature sensor connector-F-150 and Mark LT



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Fig. Fuel Rail Pressure and Temperature sensor connector-F-250 and F-350

  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Connect a mechanical fuel pressure gauge.
  4.  
  5. With the key ON and engine running, backprobe the FRPT sensor pins 1 and 4.
  6.  
  7. Compare the voltage and pressure readings with the specifications table.

    Click image to see an enlarged view

    Fig. FRPT sensor pressure specification table

  8.  
  9. Backprobe FRPT sensor pins 3 and 4.
  10.  
  11. Compare the voltage and temperature with the specification table.

    Click image to see an enlarged view

    Fig. FRPT sensor temperature specification table

  12.  

 
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