Mazda 323/MX-3/626/MX-6/Millenia/Protégé 1990-1998 and Ford Probe 1993-1997

Camshaft Position Sensor



The camshaft position sensor reads the rotation of the camshaft which the computer translates to determine engine timing sequences. The computer uses these readings to determine engine rpm and proper fuel injection and ignition timing.


See Figures 1 and 2

The camshaft position sensor requires a scan tool in order to properly test the component.

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Fig. Fig. 1: When using a scan tool, make sure to follow all of the manufacturers instructions carefully to ensure proper diagnosis

  1. Connect a scan tool to the diagnostic link.
  3. Detach the fuel injector wire harness connectors. This will ensure that the engine does not try to start and run while performing the test.

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Fig. Fig. 2: To test the camshaft position sensor, remove the distributor, connect a scan tool then rotate the distributor drive by hand

  1. Remove the distributor from the engine.
  3. Detach the 3-wire connector from the distributor.
  5. Enable the scan tool to record the camshaft position sensor output.
  7. Rotate the distributor drive by hand and verify that there were four 5 volt pulses within one revolution of the distributor drive.
  9. If not as specified, replace the distributor assembly.


The camshaft position sensor is an integral part of the distributor and not serviceable. The entire distributor assembly must be replaced. Refer to Engine Electrical for procedures involving the distributor.