Aspen 2007, Durango 2005-2007

Camshaft Position Sensor

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Description & Operation



The Camshaft Position (CMP) sensor contains a hall effect device referred to as a sync signal generator. A rotating target wheel (tone wheel) for the CMP is located at the front of the camshaft for the right cylinder head. This sync signal generator detects notches located on a tone wheel. As the tone wheel rotates, the notches pass through the sync signal generator. The signal from the CMP sensor is used in conjunction with the Crankshaft Position Sensor (CKP) to differentiate between fuel injection and spark events. It is also used to synchronize the fuel injectors with their respective cylinders.

When the leading edge of the target wheel notch enters the tip of the CMP, the interruption of magnetic field causes the voltage to switch high, resulting in a sync signal of approximately 5 volts. When the trailing edge of the target wheel notch leaves the tip of the CMP, the change of the magnetic field causes the sync signal voltage to switch to 0 volts.

4.7L

The Camshaft Position Sensor (CMP) on the 4.7L V8 engine is bolted to the front/top of the right cylinder head. The CMP sensor contains a hall effect device called a sync signal generator to generate a fuel sync signal. This sync signal generator detects notches located on a tone wheel. The tone wheel is located at the front of the camshaft for the right cylinder head. As the tone wheel rotates, the notches pass through the sync signal generator. The pattern of the notches (viewed counter-clockwise from front of engine) is: 1 notch, 2 notches, 3 notches, 3 notches, 2 notches 1 notch, 3 notches and 1 notch. The signal from the CMP sensor is used in conjunction with the crankshaft position sensor to differentiate between fuel injection and spark events. It is also used to synchronize the fuel injectors with their respective cylinders.

Exc. 4.7L

The Camshaft Position (CMP) sensor is located in the distributor. The sensor contains a Hall effect device called a sync signal generator to generate a fuel sync signal. This sync signal generator detects a rotating pulse ring (shutter) on the distributor shaft. The pulse ring rotates 180 degrees through the sync signal generator. Its signal is used in conjunction with the Crankshaft Position (CKP) sensor to differentiate between fuel injection and spark events. It is also used to synchronize the fuel injectors with their respective cylinders.

When the leading edge of the pulse ring (shutter) enters the sync signal generator, the following occurs: The interruption of magnetic field causes the voltage to switch high resulting in a sync signal of approximately 5 volts. When the trailing edge of the pulse ring (shutter) leaves the sync signal generator, the following occurs: The change of the magnetic field causes the sync signal voltage to switch low to 0 volts.

Removal & Installation



  1. Raise and safely support the vehicle.
  2.  
  3. Disconnect the CMP electrical connector.
  4.  
  5. Remove the CMP sensor mounting bolts.
  6.  
  7. Carefully twist the sensor from the cylinder.
  8.  

To install:

  1. Check the condition of the sensor O-ring.
  2.  
  3. Clean out the machined hole in the cylinder head.
  4.  
  5. Apply a small amount of clean engine oil to the sensor O-ring.
  6.  
  7. Install the CMP sensor into the cylinder head with a slight rocking and twisting action.
  8.  
  9. Install the mounting bolt and tighten to 106 inch lbs. (12 Nm).
  10.  
  11. Connect the electrical connector.
  12.  
  13. Lower the vehicle.
  14.  

4.7L
  1. The Camshaft Position Sensor (CMP) on the 4.7L V8 engine is bolted to the front/top of the right cylinder head.
    NOTE
    It is easier to remove/install sensor from under vehicle.

  2.  
  3. Raise and support vehicle.
  4.  
  5. Disconnect electrical connector at CMP sensor.
  6.  
  7. Remove sensor mounting bolt.
  8.  
  9. Carefully twist sensor from cylinder head.
  10.  
  11. Check condition of sensor O-ring.
  12.  

To Install:

  1. The Camshaft Position Sensor (CMP) on the 4.7L V8 engine is bolted to the front/top of the right cylinder head.
  2.  
  3. Clean out machined hole in cylinder head.
  4.  
  5. Apply a small amount of engine oil to sensor O-ring.
  6.  
  7. Install sensor into cylinder head with a slight rocking action. Do not twist sensor into position as damage to O-ring may result.
    WARNING
    Before tightening sensor mounting bolt, be sure sensor is completely flush to cylinder head. If sensor is not flush, damage to sensor mounting tang may result.

  8.  
  9. Install mounting bolt and tighten to 12 Nm (106 inch lbs.) torque.
  10.  
  11. Connect electrical connector to sensor.
  12.  
  13. Lower vehicle.

    Click image to see an enlarged view

    Fig.

  14.  

Exc. 4.7L
  1. The camshaft position sensor is located in the distributor on all 2.5/3.9/5.2/5.9L engines.
    NOTE
    Distributor removal is not necessary to remove camshaft position sensor.

  2.  
  3. Remove air cleaner assembly.
  4.  
  5. Disconnect negative cable from battery.
  6.  
  7. Remove distributor cap from distributor (two screws).
  8.  
  9. Disconnect camshaft position sensor wiring harness from main engine wiring harness.
  10.  
  11. Remove distributor rotor from distributor shaft.
  12.  
  13. Lift the camshaft position sensor assembly from the distributor housing.
  14.  

To Install:

  1. Install camshaft position sensor to distributor. Align sensor into notch on distributor housing.
  2.  
  3. Connect wiring harness.
  4.  
  5. Install rotor.
  6.  
  7. Install distributor cap. Tighten mounting screws.
  8.  
  9. Install air cleaner assembly.

    Click image to see an enlarged view

    Fig.

  10.  

Testing



  1. Using a diagnostic scan tool, check for the presence of any Diagnostic Trouble Codes (DTCs). Record and address these codes as necessary.
  2.  
  3. Turn the ignition OFF and disconnect the Camshaft Position (CMP) Sensor harness connector.
    NOTE
    If any of the test results fall outside of the specification, stop and repair the affected component.

  4.  
  5. With the Ignition on, and engine not running, measure the voltage on the (F856) 5-volt Supply circuit in the CMP Sensor harness connector. Is the voltage between 4.5 and 5.2 volts-
  6.  
  7. If it is, measure the voltage on the (K44) CMP Signal circuit in the CMP Sensor harness connector. The voltage should be between 4.5 and 5.0 volts.
  8.  
  9. If it is, turn the ignition off and disconnect the C2 ECM harness connector.
    CAUTION
    Do not probe the ECM harness connectors. Probing the ECM harness connectors will damage the ECM terminals resulting in poor terminal to pin connection. Install Miller Special Tool no. 8815 to perform diagnosis.

  10.  
  11. Measure the resistance of the (K900) Sensor ground circuit from the CMP Sensor harness connector to the appropriate terminal of special tool No. 8815. If the resistance is below 5.0 ohms, proceed to the next step, otherwise repair the open ground in the K900 sensor.
  12.  
  13. Measure the resistance between the (K44) CMP Signal circuit and the (F856) 5-volt Supply circuit in the CMP Sensor harness connector. If the resistance is below 5.0 ohms, repair the short between the (K44) CMP Signal circuit and the (F856) 5-volt Supply circuit.
    NOTE
    Inspect the Camshaft sprocket for damage per the Service Information. If a problem is found repair as necessary.

  14.  

 
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