Aspen 2007, Durango 2005-2007

Crankshaft Position Sensor

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Operation



Engine speed and crankshaft position are provided through the CKP sensor. The sensor generates pulses that are the input sent to the Powertrain Control Module (PCM). The PCM interprets the sensor input to determine the crankshaft position. The PCM then uses this position, along with other inputs, to determine injector sequence and ignition timing.

The sensor is a hall effect device combined with an internal magnet. It is also sensitive to steel within a certain distance from it.

The sensor generates pulses that are the input sent to the Electronic Control Module (ECM). The ECM interprets the sensor input to determine the crankshaft position and engine speed.

The sensor is a hall effect device combined with an internal magnet. It is also sensitive to steel within a certain distance from it. A tonewheel is bolted to the engine crankshaft. The tonewheel has notches that cause a pulse to be generated when they pass under the sensor.

2.5L

The Crankshaft Position (CKP) sensor is located near the outer edge of the flywheel (or starter ring gear).

The flywheel/drive plate has groups of four notches at its outer edge. On 2.5L 4-cylinder engines there are two sets of notches. The notches cause a pulse to be generated when they pass under the sensor. The pulses are the input to the PCM. For each engine revolution there are two groups of four pulses generated on 2.5L 4-cylinder engines.

The trailing edge of the fourth notch, which causes the pulse, is four degrees before top dead center (TDC) of the corresponding piston. The engine will not operate if the PCM does not receive a CKP sensor input.

3.7L V6

The Crankshaft Position (CKP) sensor (2) is mounted into the right rear side of the cylinder block. It is positioned and bolted into a machined hole.

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Fig.

3.7L V6 & 4.7L V8

A tone wheel (target wheel) is bolted to the engine crankshaft (1). This tone wheel has sets of notches (2) at its outer edge. The notches cause a pulse to be generated when they pass under the sensor. The pulses are the input to the PCM.

Click image to see an enlarged view

Fig.

3.9L

The Crankshaft Position (CKP) sensor is located near the outer edge of the flywheel (starter ring gear).

4.7L

The Crankshaft Position Sensor (CKP) is mounted into the right-rear side of the engine block.

Click image to see an enlarged view

Fig.

On the 4.7L V8 engine, a tone wheel is bolted to the engine crankshaft. This tone wheel has sets of notches at its outer edge. The notches cause a pulse to be generated when they pass under the sensor. The pulses are the input to the PCM.

5.2L & 5.9L

The Crankshaft Position (CKP) sensor is located near the outer edge of the flywheel (starter ring gear).

On 5.2/5.9L V-8 engines, the flywheel/drive plate has 8 single notches, spaced every 45 degrees, at its outer edge. The notches cause a pulse to be generated when they pass under the sensor. The pulses are the input to the PCM. For each engine revolution, there are 8 pulses generated on V-8 engines. The engine will not operate if the PCM does not receive a CKP sensor input.

Removal & Installation



  1. Raise and safely support the vehicle.
  2.  
  3. Disconnect the sensor electrical connector.
  4.  
  5. Remove the crankshaft position (CKP) sensor mounting bolt.
  6.  
  7. Carefully twist the CKP sensor from the cylinder block.
  8.  

To install:

  1. Check the condition of the O-ring.
  2.  
  3. Clean out the machined hole in the engine block.
  4.  
  5. Apply a small amount of clean engine oil to the sensor O-ring.
  6.  
  7. Install the CKP sensor into the engine block with a slight rocking and twisting action.
  8.  
  9. Install the mounting bolt and tighten to 21 ft. lbs. (28 Nm).
  10.  
  11. Connect the electrical connector.
  12.  
  13. Lower the vehicle.
  14.  

2.5L Engines
  1. Remove air tube between throttle body and air cleaner housing.
  2.  
  3. Near rear of intake manifold, disconnect pigtail harness (on the sensor) from main electrical harness.
  4.  
  5. Remove 2 sensor mounting bolts.
  6.  
  7. Remove sensor.
  8.  
  9. Remove clip from sensor wire harness.
  10.  

To Install:

  1. Install sensor flush against opening in transmission housing.
  2.  
  3. Install and tighten two sensor mounting bolts to 12 Nm (9 ft. lbs.) torque.
    WARNING
    wo bolts are used to secure the sensor to transmission. These bolts are specially machined to correctly space the unit to flywheel. Do not attempt to install any other bolts.

  4.  
  5. Connect electrical connector to sensor.
  6.  
  7. Install clip on sensor wire harness.
  8.  
  9. Install air tube between throttle body and air cleaner housing.
  10.  

3.7L
  1. Raise vehicle.
  2.  
  3. Disconnect sensor electrical connector.
  4.  
  5. Remove sensor mounting bolt (1).
  6.  
  7. Carefully twist sensor from cylinder block.
  8.  
  9. Check condition of sensor O-ring (3).
  10.  

To Install:

  1. Clean out machined hole in engine block.
  2.  
  3. Apply a small amount of engine oil to sensor O-ring (3).
  4.  
  5. Install sensor (2) into engine block with a slight rocking and twisting action.
    WARNING
    Before tightening sensor mounting bolt (1), be sure sensor is completely flush to cylinder block. If sensor is not flush, damage to sensor mounting tang may result.

  6.  
  7. Install mounting bolt (1) and tighten to 28 Nm (21 ft. lbs.) torque.
  8.  
  9. Connect electrical connector to sensor.
  10.  
  11. Lower vehicle.
  12.  

3.9L, 5.2L & 5.9L
  1. Remove right front tire and right front wheelhouse liner.
  2.  
  3. Disconnect crankshaft position sensor pigtail harness from main wiring harness.
  4.  
  5. Remove two sensor (recessed hex head) mounting bolts.
  6.  
  7. Remove sensor from engine.
  8.  

To Install:

  1. Position crankshaft position sensor to engine.
  2.  
  3. Install mounting bolts and tighten to 8 Nm (70 inch lbs.) torque.
  4.  
  5. Connect main harness electrical connector to sensor.
  6.  
  7. Install right front tire and right front wheelhouse liner.
  8.  

4.7L
  1. Disconnect CKP electrical connector at sensor.
  2.  
  3. Remove CKP mounting bolt.
  4.  
  5. Carefully twist sensor from cylinder block.
  6.  
  7. Remove sensor from vehicle.
  8.  
  9. Check condition of sensor O-ring.
  10.  

To Install:

  1. Clean out machined hole in engine block.
  2.  
  3. Apply a small amount of engine oil to sensor O-ring.
  4.  
  5. Install sensor into engine block 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 block. If sensor is not flush, damage to sensor mounting tang may result.

  6.  
  7. Install mounting bolt and tighten to 28 Nm (21 ft. lbs.) torque.
  8.  
  9. Connect electrical connector to sensor.
  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. Disconnect the Crankshaft Position (CKP) Sensor harness connector.
    NOTE
    If 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 (F855) 5-volt Supply circuit in the CKP Sensor harness connector. Voltage should be between 4.5 and 5.2 volts.
  6.  
  7. If it is, measure the voltage on the (K24) CKP Signal circuit in the CKP Sensor harness connector. The sensor voltage should be approximately 5.0 volts (plus or minus .1 volt) with the connector disconnected.
  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 CKP Sensor harness connector to the appropriate terminal of special tool No. 8815. Resistance should be below 5.0 ohms.
  12.  
  13. If it is, measure the resistance between the (K24) CKP Signal circuit and the (F855) 5-volt Supply circuit in the CKP Sensor harness connector. If the resistance below 5.0 ohms, repair the short between the (K24) CKP Signal circuit and the (F855) 5-volt Supply circuit.
  14.  
  15. If not, replace the crankshaft position sensor.
  16.  

 
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