Volkswagen Cars 2000-05

Camshaft Position Sensor

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The camshaft position sensor on the AAA engine is mounted on the side of the cylinder head, next to the coil pack. This sensor provides a signal to the ECM regarding the position of the camshaft.

Although the camshaft position sensor is an essential input for the ECM to determine ignition timing, information on testing the sensor is located in Section 4 of this manual.

The camshaft position sensor is mounted on the cylinder head. This sensor provides a signal to the ECM regarding the relative position of the camshaft.

The crankshaft position sensor is an essential input for the ECM to determine ignition timing. For additional information, please refer to the following topic(s): Driveability and Emission Controls, Camshaft Position Sensor.

Description & Operation



The camshaft position sensor provides information on the camshaft position. The ECM uses this information, along with the engine speed sensor information, to control the ignition timing and fuel injection synchronization.

2.0L 9a & Aba Engines

The Camshaft Position (CMP) Sensor on these engines is actually a Hall-effect type sensor, which is located in the distributor. This sensor provides a signal to the ECM regarding the position of the crankshaft.

On the 2.0L 9A engines the Hall-effect sensor in the distributor is used as the speed and reference sensor by the control module. The inductive pick up around the No. 4 spark plug wire serves as the reference sensor for cylinder identification for the control module.

On the 2.0L ABA engines the Hall-effect sensor in the distributor is used as the cylinder position reference sensor by the control module. On these engines, the Crankshaft Position (CKP) sensor is used to calculate engine speed.

The Camshaft Position (CMP) Sensor is an essential input for the ECM to determine ignition timing. For additional information, please refer to the following topic(s): Electronic Engine Controls, Camshaft Position Sensor

Digifant, Mono-Motronic, & CIS-Motronic

The "camshaft" position sensor on these engines is actually a Hall-effect type sensor, which is located in the distributor. This sensor performs the same function as a crankshaft position sensor; providing a signal to the ECM regarding the position of the crankshaft.

Although the camshaft position sensor is an essential input for the ECM to determine ignition timing, information on testing the sensor is located in Section 4 of this manual.

Removal & Installation



1.8L Engines


Click image to see an enlarged view

Fig. Showing the 1.8L engine camshaft position sensor

  1. Disconnect the electrical connector for the sensor.
  2.  
  3. Remove the timing belt upper cover.
  4.  
  5. Remove the housing for the sensor.
  6.  

2.7L & 2.8L


Click image to see an enlarged view

Fig. Here is the CMP sensor used on the 2.7L & 2.8L engines

Key list for gnam 93224vwg56:

13-CMP sensor, cylinder bank 2

17-Harness connector

18-CMP sensor, cylinder bank 1

Testing



1.8L Engines

NOTE
Battery voltage must be 11.5 volts minimum before starting any testing.



Click image to see an enlarged view

Fig. Showing the 3-pin camshaft position sensor connector

  1. Disconnect camshaft position sensor 3-pin harness connector.
  2.  
  3. Switch the DMM to the voltage measurement range.
  4.  
  5. Connect the DMM between the outer terminals of connector, using jumper wires from VW 1594.
  6.  
  7. Switch the ignition to 'ON', but Do NOT start the engine. You should see a minimum of 4.5 volts.
  8.  
  9. Now, switch the ignition 'OFF'.
  10.  
  11. Connect a test box VAG 1598/22 to the ECM harness connector.
  12.  
  13. Check the wiring between the test box and the ECM harness connector, using a wiring diagram. Checks should be made at each of the following points:
  14.  


    Terminal 1 and socket 11
     
    Terminal 2 and socket 76
     
    Terminal 3 and socket 67
     

  15. For each of the above checks, the maximum resistance should not exceed 1.5 ohms.
  16.  
  17. Check all wires for shorting to one another. If these are not shorted, there should be infinite ohms on each wire.
  18.  
  19. If wiring the OK and there is voltage present between terminals 1 and 3 , replace the camshaft position sensor.
  20.  
  21. If wiring is OK, but NO voltage is present between terminals 1 and 3 , replace the ECM.
  22.  

2.8L

NOTE
Battery voltage must be 11.5 volts minimum before starting any testing.



Click image to see an enlarged view

Fig. Camshaft position sensor connectors on 2.8L engines

  1. Disconnect the 3-pin harness connectors from the Camshaft Position (CMP) sensors.
  2.  


    A-CMP sensor, cylinder bank 1, right front
     
    B-CMP sensor, cylinder bank 2, left rear
     




Click image to see an enlarged view

Fig. Identifying terminal locations on the camshaft position sensor connector (2.8L engines)

  1. Connect the DMM to measure voltage across the CMP connector terminals 1 (B+) and 3 (Ground), using adapters from VW1594 connector test kit.
  2.  
  3. Switch ignition to 'ON', but Do NOT start engine.
  4.  
  5. Measure voltage between terminals 1 and 3 . There should be a minimum 9.0 volts.
  6.  
  7. Switch the ignition 'OFF'.
  8.  
  9. Connect a VAG1598/22 test box to the ECM harness connector.
  10.  
  11. Check the wiring for open circuit between the ECM test box and 3-pin harness connector, according to the wiring diagram.
  12.  
  13. For the CMP sensor connector on the right cylinder head, measure as follows:
  14.  


    Connector terminal 1 to ECM test box socket 11
     
    Connector terminal 2 to ECM test box socket 76
     
    Connector terminal 3 to ECM test box socket 67
     


For these checks, the specification should show a maximum resistance of 1.5 ohms.

  1. For the CMP sensor on the left cylinder head, measure as follows:
  2.  


    Connector terminal 1 to ECM test box socket 11
     
    Connector terminal 2 to ECM test box socket 44
     
    Connector terminal 3 to ECM test box socket 14
     


For each of these checks, the specification should show a maximum resistance of 1.5 ohms.

  1. Check the wiring for short circuits to one another. The DMM should show infinite ohms.
  2.  
  3. If the wiring is OK, and voltage across terminals 1 and 3 is OK, replace camshaft position sensor.
  4.  
  5. If the wiring is OK, but there is still no voltage across terminals 1 and 3 , replace the ECM.
  6.  

CMP Sensor Functional Test
  1. For a functional check of camshaft position sensor, disconnect the 4-pin connector from the ignition coil power output stage and check DTC memory.
  2.  
  3. Check the camshaft position sensor voltage supply and ensure it is OK.
  4.  
  5. Push back the rubber boot on the CMP sensor connector (sensor remains connected).
  6.  
  7. Connect a VAG 1527B voltage tester between terminal 1 (B+) and 2 (signal).
  8.  
  9. Crank the engine over for several seconds.
  10.  
  11. The voltage tester must flash briefly for every second engine rotation.
  12.  

If voltage tester does not flash, switch the ignition off and disconnect the 3-pin harness connector from the camshaft position sensor.

  1. Connect a VAG 1598/19 test box to the ECM harness connector.
  2.  
  3. Check the signal wire for continuity between harness connector terminal 2 and test box socket B2 . There should be a maximum resistance of 1 ohm.
  4.  
  5. If the specified value is not obtained, check for possible short or open circuit in wiring between the CMP sensor harness connector and the ECM harness connector.
  6.  
  7. If the wiring is OK, connect a DMM between test box socket B2 and a vehicle ground.
  8.  
  9. Turn the ignition switch to 'ON'. There should be a minimum of 4.0 volts.
  10.  
  11. If the specified value is not obtained, replace the ECM.
  12.  
  13. If the specified value is obtained, replace the Camshaft Position (CMP) sensor.
  14.  

 
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