GM Cavalier/Sunfire 1995-2000 Repair Guide

Camshaft Position (CMP) Sensor

Print

OPERATION



See Figures 1 and 2



Click image to see an enlarged view

Fig. Fig. 1: The CMP is located on the side of the block under the intake manifold-2.2L engine

The PCM uses the camshaft signal to determine the position of the No. 1 cylinder piston during its power stroke. The signal is used by the PCM to calculate fuel injection mode of operation.

If the cam signal is lost while the engine is running, the fuel injection system will shift to a calculated fuel injected mode based on the last fuel injection pulse, and the engine will continue to run.



Click image to see an enlarged view

Fig. Fig. 2: Camshaft Position (CMP) sensor location-2.2L engines

TESTING



See Figures 3, 4 and 5

  1. Remove the PCM fuse to prevent the engine from starting. Removal of the PCM fuse does not disable the sensor power supply and allows testing of this sensor safely.
  2.  
  3. Disconnect the CMP sensor wiring harness and attach suitable jumper wires between the CMP sensor and CMP sensor harness. Connect a DC volt meter to the jumper wires corresponding to CMP IGN or PWR terminal and sensor ground.
  4.  
  5. With the ignition ON and the engine off, verify that the voltage is approximately battery voltage. The supply voltage should be slightly less than battery voltage.
  6.  
  7. If not as specified, repair or replace the fuse and/or wiring.
  8.  
  9. Connect a DC volt meter to the jumper wires corresponding to CMP signal terminal and sensor ground.
  10.  
  11. Place a socket and breaker bar or the crankshaft pulley bolt and rotate the engine slowly by hand. Observe the volt meter and verify that the voltage signal varies from approximately zero volts to slightly less than supply voltage. The voltage will switch on when the target passes the sensor and will show little or no voltage when the target is past the sensor.
  12.  
  13. If it is not as specified, the CMP sensor may be faulty.
  14.  



Click image to see an enlarged view

Fig. Fig. 3: Common Camshaft Position (CMP) sensor wiring schematic-2.2L engines (wire color, terminal identification/location may vary on certain models)



Click image to see an enlarged view

Fig. Fig. 4: Attach suitable jumper wires between the CMP sensor and CMP sensor harness. Connect a DC volt meter to the jumper wires corresponding to IGN and sensor ground terminals and note the reading



Click image to see an enlarged view

Fig. Fig. 5: Connect the volt meter to the jumper wire corresponding to signal and sensor ground terminals, rotate the engine and observe the volt meter and verify that the voltage signal varies from approximately zero volts to slightly less than supply voltage

REMOVAL & INSTALLATION



2.2L Engines

See Figures 6, 7 and 8

  1. Disconnect the negative battery cable.
  2.  
  3. Raise the vehicle and support it with safety stands.
  4.  
  5. Remove the right hand tire assembly.
  6.  
  7. Unplug the sensor harness connector at the sensor.
  8.  
  9. Unfasten the retaining bolt, then remove the sensor from the camshaft housing.
  10.  



Click image to see an enlarged view

Fig. Fig. 6: The Camshaft Position (CMP) sensor-2.2L engine



Click image to see an enlarged view

Fig. Fig. 7: The Camshaft Position (CMP) sensor-2.3L/2.4L engines



Click image to see an enlarged view

Fig. Fig. 8: Unplug CMP sensor electrical connection and unfasten the sensor retainer, then remove the sensor from its bore in the block-2.2L engine

To install:
  1. Place the sensor into position.
  2.  
  3. Install the CMP sensor retaining bolt, then tighten to 88 inch lbs. (10 Nm).
  4.  
  5. Attach the sensor harness connector.
  6.  
  7. Install the tire assembly and lower the vehicle.
  8.  
  9. Connect the negative battery cable.
  10.  

2.3L/2.4L Engines
  1. Disconnect the negative battery cable.
  2.  
  3. Unplug the sensor harness connector at the sensor.
  4.  
  5. Unfasten the retaining bolt, then remove the sensor from the camshaft housing.
  6.  

To install:
  1. Place the sensor into position.
  2.  
  3. Install the CMP sensor retaining bolt, then tighten to 88 inch lbs. (10 Nm).
  4.  
  5. Attach the sensor harness connector.
  6.  
  7. Connect the negative battery cable.
  8.  

 
label.common.footer.alt.autozoneLogo