Nissan Sentra/Pulsar/NX 1982-1996 Repair Guide

Crankshaft Position Sensor (CKPS)



See Figure 1

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Fig. Fig. 1: Cross-sectional view of the crankshaft position sensor

Beginning in 1995, the GA16DE and SR20DE engines use a crankshaft position sensor. The sensor is mounted to the transaxle housing, just above the flywheel. The sensor consists of a magnet, a core and a coil. There is preset clearance between the sensor face and ring gear teeth. As the ring gear teeth rotate past the sensor, the air gap (clearance) changes, disrupting the magnetic field around the sensor, creating a voltage change on the sensor signal line. The rate of change is detected by the ECM, thus enabling the ECM to determine the engine rpm. This signal is used in conjunction with other inputs, to detect an engine misfire, and is not used to control either the fuel or ignition timing.


See Figures 2 and 3

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Fig. Fig. 2: Visually inspect the crankshaft position sensor for damage or dirt build-up, at the indicated point

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Fig. Fig. 3: To test the crankshaft position sensor, connect an ohmmeter across the sensor terminals, as shown

  1. Remove the crankshaft position sensor from the transaxle housing.
  3. Visually inspect the sensor tip for dirt build-up or damage.

On vehicles equipped with a manual transaxle, dirt build-up from clutch material is a common cause of failure.

If the sensor is okay, proceed to the next step.
If the sensor has excessive dirt build-up, carefully clean the sensor.

Do not use a wire brush or any other abrasive material to clean the sensor tip.

If the sensor is damaged, replace the sensor and retest.

  1. Connect an ohmmeter across the sensor terminals and measure the resistance. The resistance reading at 77°F (25°C) should be as follows:

    GA16DE engine with M/T-432-528 ohms
    GA16DE engine with A/T-166-204 ohms
    SR20DE engine-166-204 ohms

  3. If the measured value is not within specifications, replace the crankshaft position sensor.


  1. Disconnect the electrical connector from the sensor.
  3. Remove the mounting bolt and lift the sensor its bore.
  5. Installation is the reverse of the removal procedure.