PT Cruiser, 2001 - 2005

Camshaft Position (CMP) Sensor

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Description & Operation



The camshaft position sensor is mounted to the rear of the cylinder head. The sensor also acts as a thrust plate to control camshaft endplay.

The PCM sends approximately 5 volts to the Hall-effect sensor. This voltage is required to operate the Hall-effect chip and the electronics inside the sensor. The input to the PCM occurs on a 5-volt output reference circuit. A ground for the sensor is provided through the sensor return circuit. The PCM identifies camshaft position by registering the change from 5 to 0 volts, as signaled from the Camshaft Position sensor.

On 2.0/2.4L engines a target magnet attaches to the rear of the camshaft and indexes to the correct position. The target magnet has fourteen different poles arranged in an asymmetrical pattern. As the target magnet rotates, the camshaft position sensor senses the change in polarity.

The PCM determines fuel injection synchronization and cylinder identification from inputs provided by the camshaft position sensor (2.0L and 2.4L) and crankshaft position sensor. From the two inputs, the PCM determines crankshaft position.

The sensor input switches from high (5 volts) to low (0.30 volts) as the target magnet rotates. When the north pole of the target magnet passes under the sensor, the output switches high. The sensor output switches low when the south pole of the target magnet passes underneath.

On 1.6L a raised platform on the cam sprocket serves as a target. When the sensor detects the step, the input voltage from the sensor to the PCM switches from high (5 volts) to low (0.3 volts). As the step returns away from the sensor, the input voltage switches back to high (5 volts).

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Fig.

Removal & Installation



2.0L & 2.4L
  1. Remove the air cleaner lid, disconnect the inlet air temperature sensor and makeup air hose.
  2.  
  3. Remove the negative battery cable.
  4.  
  5. Disconnect electrical connector from camshaft position sensor.
  6.  
  7. Remove camshaft position sensor mounting screws. Remove sensor.
  8.  
  9. Loosen screw attaching target magnet to rear of camshaft.
  10.  

To install:

  1. The target magnet has locating dowels that fit into machined locating holes in the end of the camshaft.
    WARNING
    Installation of the electrical connector or sensor at an angle may damage the sensor pins.

  2.  
  3. Install target magnet in end of camshaft. Tighten mounting screw to 3.6 Nm (32 5 inch lbs.) torque. Over-torquing could cause cracks in magnet. If magnet cracks replace it.
  4.  
  5. Install camshaft position sensor. Tighten sensor mounting screws to 13 Nm (115 15 inch lbs.) torque.
  6.  
  7. Carefully attach electrical connector to camshaft position sensor.
  8.  
  9. Install the negative battery cable.
  10.  
  11. Install the air cleaner lid; connect the inlet air temperature sensor and makeup air hose.
  12.  

 
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