Alphabetical Index

Driveability & Emissions Controls
ELECTRONIC ENGINE CONTROLS

Crankshaft Position Sensor (CKP)




TESTING
See Figure 1
Fig. 1: Testing a crankshaft position sensor

Except SVX


  1. Disconnect the CKP sensor harness.
  2. Connect a voltmeter across the CKP sensor terminals.
  3. Crank the engine. Voltage should vary around 0.1 volt alternating current and in time with engine movement.
  4. If the CKP sensor tests satisfactorily, check the CKP sensor harness.

SVX

  1. Remove the CKP sensor from the engine.
  2. Connect a lab-type oscilloscope across the CKP terminals. Set the voltage scale to low level.
  3. Wave a magnet past the CKP pickup area. The magnet should pass as close as possible without contacting the CKP sensor.
  4. Examine the waveform on the oscilloscope as the magnet passes pickup. A waveform should appear as the magnet passes. If no waveform is present, replace the CKP sensor.

REMOVAL & INSTALLATION

Impreza


See Figures 2 and 3

Fig. 2: Crankshaft position sensor attached to the cylinder block-Impreza

Fig. 3: After removing the retainer bolt, lift the sensor out-Impreza
  1. Disconnect the negative battery cable.
  2. Disconnect the electrical harness from the crankshaft position sensor.
  3. Remove the crankshaft position sensor-to-engine bolt, then the crankshaft position sensor from the engine; be careful not damage the electrical wiring.

To install:

  1. Install the crankshaft position sensor to the engine, and tighten the bolt to 36 ft. lbs. (49 Nm).
  2. Connect the crankshaft position sensor harness.
  3. Connect the negative battery cable.

Legacy

  1. Disconnect the negative battery cable.
  2. Remove the timing belt.
  3. Remove the crankshaft position sensor-to-cylinder block bolt, then the crankshaft position sensor from the engine; be careful not damage the electrical wiring.
  4. Disconnect the electrical harness, and remove the crankshaft position sensor from the engine.

To install:

  1. Install the crankshaft position sensor to the engine, and tighten the bolt to 4 ft. lbs. (5 Nm).
  2. Install the timing belt.
  3. Connect the crankshaft position sensor harness.
  4. Connect the negative battery cable.

SVX

This vehicle is equipped with 2 crankshaft position sensors.

  1. Disconnect the negative battery cable.
  2. Remove the timing belt.
  3. Remove the crankshaft position sensor-to-oil pump bolt, then the crankshaft position sensor from the engine; be careful not damage the electrical wiring.
  4. Disconnect the electrical harness and remove the crankshaft position sensor from the engine.

To install:

  1. Install the crankshaft position sensor to the oil pump, and tighten the bolt to 4 ft. lbs. (5 Nm).
  2. Install the timing belt.
  3. Connect the crankshaft position sensor harness.
  4. Connect the negative battery cable.


END OF SECTION