Mazda B-Series 1998-06

Crankshaft Position Sensor

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Operation



The Crankshaft Position Sensor, on all 1994-95 MPV models, is an integral component of the distributor assembly.

The Crankshaft Position (CKP) sensor, located on the front cover (near the crankshaft pulley) is used to determine crankshaft position and crankshaft rpm. The CKP sensor is a reluctance sensor which senses the passing of teeth on a sensor ring because the teeth disrupt the magnetic field of the sensor. This disruption creates a voltage fluctuation, which is monitored by the PCM.



Click image to see an enlarged view

Fig. The CKP sensor (A) is triggered by the teeth which are machined into the crankshaft damper (B)

The crankshaft position sensor reads the rotation of the crankshaft, which the computer translates to determine engine-timing sequences. The computer uses this reading, in conjunction with the camshaft position sensor, to determine proper fuel injection and ignition timing.

Removal & Installation



  1. Disconnect the negative battery cable.
  2.  
  3. Remove the necessary accessory drive belts to access the sensor.
  4.  
  5. If necessary, remove the engine oil dipstick tube.
  6.  
  7. Remove the sensor-attaching bolt, and then withdraw the sensor from the engine.
  8.  
  9. Installation is the reverse of the removal procedure.
  10.  

Installation

NOTE
Perform the following procedure so that piston No.1 is at the top dead center.

  1. Remove the right side driveshaft.
  2.  
  3. Remove the cylinder block lower blind plug and install the special service tool or equivalent.
  4.  
  5. Turn the crankshaft pulley to the clockwise until it stops.
  6.  
  7. Using a straight edge, draw a straight line directly in the center of the ninth tooth of the crankshaft pulley pulse wheel (counting counterclockwise from the empty space).
    NOTE
    If the line is not accurately drawn, ignition timing, fuel injection and other engine control systems will be adversely affected. Drawn the straight line carefully using a straight edge.

  8.  
  9. Align the centerline of the crankshaft position sensor and the line drawn, then install the sensor.
  10.  
  11. Install the CKP sensor fitting bolts. Tightening torque 4.1-5.5 ft lbs
  12.  
  13. Remove the special service tool or equivalent then install the cylinder block lower blind plug. Tightening torque 15 ft lbs
  14.  
  15. Install the right side driveshaft.
  16.  
  17. Install the splash shield.
  18.  
  19. Install the right front wheel
  20.  

Removal
  1. Remove the right front wheel.
  2.  
  3. Remove the splash shield.
  4.  
  5. Disconnect the CKP sensor connector.
  6.  
  7. Remove the installation bolts to remove the CKP sensor.

    Click image to see an enlarged view

    Fig.



    Click image to see an enlarged view

    Fig.



    Click image to see an enlarged view

    Fig.

  8.  

Testing



  1. Disconnect the crankshaft position sensor wire harness plug.
  2.  
  3. Connect an ohmmeter to the sensor terminals A and B and measure the resistance.
  4.  
  5. The reading should be 520-580 ohms at 68°F.
  6.  
  7. If not as specified, replace the sensor.
  8.  
  9. Measure the air gap of the sensor between the crankshaft pulley and the sensor.
  10.  
  11. Proper air gap should be 0.040-0.080 in.
  12.  
  13. If not as specified, inspect the crankshaft pulley and/or replace the sensor.
  14.  

 
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