Hyundai Coupes/Sedans 1994-1998 Repair Guide

Crankshaft Position (CKP) Sensor

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OPERATION



The signal from the CKP sensor which provides both engine rpm and crankshaft position is sent to the ECM. The ECM computes the engine speed and control the fuel injection timing and ignition timing based on the signal. On early model engines, the CKP and CMP are combined and mounted on the cylinder head. On late model engines, the CKP is mounted on the engine near the flywheel.

TESTING



See Figures 1 and 2



Click image to see an enlarged view

Fig. Fig. 1: Crankshaft position sensor schematic-early model engines



Click image to see an enlarged view

Fig. Fig. 2: Crankshaft position sensor schematic-late model engines

Early Model Engines

Crankshaft position sensors for early model engines can be identified by a 4 terminal connector.

  1. Backprobe the sensor electrical harness with the ignition ON .
  2.  
  3. Measure voltage between sensor terminals 1 and 4 while cranking the engine around slowly.
  4.  
  5. Voltage should alternate between 0-5.0 volts.
  6.  
  7. If voltage does not alternate, check power and ground circuits.
  8.  
  9. If power and ground circuits are functional, sensor is faulty.
  10.  

Late Model Engines

Crankshaft position sensors for early model engines can be identified by a 3 terminal connector.

  1. Backprobe the sensor electrical harness between sensor terminals 2 and 3 with the engine running.
    1. Voltage should be greater than 0.1 volts and increase with engine rpm.
    2.  
    3. If voltage is not within specification, check sensor resistance.
    4.  

  2.  
  3. Disconnect the sensor electrical harness.
  4.  
  5. Measure the resistance between sensor terminals 2 and 3.
    1. Resistance should be 4.8-5.6 ohms @ 68°F.
    2.  
    3. If resistance is not within specification, ensure clearance between CKP and flywheel is 0.020-0.059 in . (0.5-1.5 mm). Adjust sensor clearance as necessary.
    4.  
    5. If sensor resistance or voltage is still not within specification, sensor is faulty.
    6.  

  6.  

REMOVAL & INSTALLATION



Flywheel Mounted Sensor
  1. Disconnect the negative battery cable.
  2.  
  3. Label and disconnect the sensor electrical harness
  4.  
  5. Loosen sensor mounting bolts.
  6.  
  7. Carefully remove the sensor.
  8.  

To Install:
  1. Carefully install the sensor.
  2.  
  3. Check sensor to flywheel clearance. Clearance should be 0.020-0.059 in . (0.5-1.5 mm). Adjust as necessary.
  4.  
  5. Tighten mounting bolts to 6-8 ft. lbs. (9-11 Nm).
  6.  
  7. Connect the sensor electrical harness
  8.  
  9. Connect the negative battery cable.
  10.  

Cylinder Head Mounted Sensor
  1. Disconnect the negative battery cable.
  2.  
  3. Label and disconnect the sensor electrical harness
  4.  
  5. If sensor mounting bolts have slots for adjustment, matchmark the sensor and the cylinder head.
  6.  
  7. Loosen sensor mounting bolts.
  8.  
  9. Carefully remove the sensor.
  10.  

To Install:
  1. Carefully install the sensor and tighten mounting bolts to 6 ft. lbs. (8 Nm).
  2.  
  3. Connect the sensor electrical harness
  4.  
  5. Connect the negative battery cable.
  6.  
  7. If sensor mounting bolts have slots for adjustment, connect a timing light and adjust the ignition timing.
  8.  

 
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