Silverado 2008

Crankshaft Position (CKP) Sensor

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Location



Specific to:

Chevrolet Silverado 1500 2008

The Crankshaft Position (CKP) Sensor is located next to the crankshaft pulley on the 4.3L engine. On the 4.8L, 5.3L and 6.0L engines the sensor is located on the side of the engine block.

Operation



Specific to:

Chevrolet Silverado 1500 2008

The Crankshaft Position (CKP) Sensor is a permanent magnet output coil device that monitors the speed and position of the crankshaft. A reluctor is attached directly to the crankshaft, and is used to generate a constant signal as it passes the CKP sensor magnetic coil. The CKP Sensor utilizes system voltage (12 volts DC), or reference voltage (5 volts DC) to generate a digital output signal to the PCM that is based upon a 0.5 volt AC reference. The alternating magnetic field is used by the sensor output electronics to produce a digital pulse. The CKP sensor returns a digital ON/OFF signal pulse during each revolution of the crankshaft, with a momentary signal interrupt for the top dead center (TDC) position of the #1 cylinder. The Pulse Width Modulation pattern is used by the Powertrain Control Module (PCM) to calculate ignition timing, fuel injector timing, misfire diagnostics, and the tachometer display.

Removal & Installation



Specific to:

Chevrolet Silverado 1500 2008


NOTE
Use of a scan tool is required to complete this procedure. Anytime the CKP sensor is replaced, the variation learn procedure must be performed.

4.3L Engines

Specific to:

Chevrolet Silverado 1500 2008

  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Disconnect the negative battery cable.
  4.  
  5. Raise and support the vehicle safely.
  6.  
  7. Remove the skid plates, if equipped.

    Click image to see an enlarged view

    Fig. Skid plate and related components-type one



    Click image to see an enlarged view

    Fig. Skid plate and related components-type two

  8.  
  9. Unplug the harness connector from the sensor.
  10.  
  11. Remove the bolt securing the sensor, then remove it from the engine.

    Click image to see an enlarged view

    Fig. CKP sensor mounting-4.3L engines

  12.  

To install:


NOTE
Be sure to use new fasteners, as required.

  1. Installation is the reverse of removal.
  2.  
  3. Lubricate a new O-ring with clean engine oil.
  4.  
  5. Tighten the bolt to 89 inch lbs. (10 Nm).
  6.  
  7. Connect the scan tool to the vehicle and perform the CKP sensor variation learn procedure.
  8.  

4.8L, 5.3L & 6.0L Engines

Specific to:

Chevrolet Silverado 1500 2008

  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Disconnect the negative battery cable.
  4.  
  5. Raise and safely support the vehicle.
  6.  
  7. Remove the starter.
  8.  
  9. Working through the wheel well opening, unplug the harness connector from the sensor.
  10.  
  11. Clean the area around the sensor to prevent debris from entering the engine.
  12.  
  13. Remove the bolt securing the sensor, then remove it from the engine.

    Click image to see an enlarged view

    Fig. CKP sensor mounting-4.8L, 5.3L & 6.0L engines

  14.  

To install:


NOTE
Be sure to use new fasteners, as required.

  1. Installation is the reverse of removal.
  2.  
  3. Lubricate a new O-ring with clean engine oil.
  4.  
  5. Tighten the bolt to 18 ft. lbs. (25 Nm).
  6.  
  7. Connect the scan tool to the vehicle and perform the CKP sensor variation learn procedure.
  8.  

Testing



Specific to:

Chevrolet Silverado 1500 2008


NOTE
Refer to the Electrical Wiring Diagram for component and connector locations, connector views, and circuit-specific information.

CKP Circuit Testing

Specific to:

Chevrolet Silverado 1500 2008

Use a suitable scan tool or a Graphing Multi-Meter (GMM in order to view the CKP data.

CKP Sensor logic is based on alternating lines of magnetic flux which generate a digital ON/OFF signal to the PCM, and are based on the speed and position of the crankshaft.

Verify that the engine timing components (timing belt, timing chain, or timing gears) are properly installed, and that there is no foreign material obstructing the path between the reluctor and the CKP sensor. If any engine mechanical faults are evident, locate and repair as required before continuing.

A Digital Volt-Ohm Meter (DVOM) may be used to verify the condition of the wiring: additional information may be acquired by taking measurements at the sensor connector as well as the PCM connector. If significant resistance is measured (greater than 5 ohms), check the wiring harness and connections for corrosion, poor pin connections, or damaged wires.

If all engine wiring and pin connections are confirmed, disconnect the CKP Sensor to verify the signal with a GMM, and verify PCM communication before replacing the CKP Sensor.

Click image to see an enlarged view

Fig. CKP Sensor Range Chart

CKP Sensor Strategy

Specific to:

Chevrolet Silverado 1500 2008

The CKP Sensor provides a digital input signal (See Figure 1) to the Powertrain Control Module (PCM) for a number of engine control system calculations. The CKP signal is compared with the Camshaft Position Sensor (CMP) and Vehicle Speed Sensor (VSS) for measured operating conditions, and the Pulse Width Modulation pattern is used by the Powertrain Control Module (PCM) to calculate ignition timing, fuel injector timing, misfire diagnostics, and the tachometer display.

Connection And Wiring Diagnosis

Specific to:

Chevrolet Silverado 1500 2008

Refer to the Electrical Wiring Diagram for component and connector locations, connector views, and circuit-specific information.

Many intermittent open or short circuits may be caused by wiring harness and connector movement due to vibration, engine torque, bumps and rough pavement, etc.

  1. Test the wiring harness and connectors by performing the following tests:

    Move the related connectors and wiring while monitoring the appropriate scan tool data.
     
    Move the related connectors and wiring with the component commanded ON and OFF. Using a suitable the scan tool, observe the component operation.
     
    With the engine running, move the related connectors and wiring while monitoring component operation.
     
    If harness or connector movement affects the data displayed, the component and system operation, or the engine operation, inspect and repair the harness or connections as necessary.
     

  2.  
  3. Test the connector terminal pins and/or wiring by performing the following tests:

    Inspect for incorrect mating of the connector halves, or terminals not fully seated in the connector body.
     
    Inspect for improperly formed or damaged terminals and test for incorrect terminal tension.
     
    Inspect for poor terminal to wire connections including terminals crimped over insulation. This requires removing the terminal from the connector body.
     
    Inspect for corrosion or water intrusion. Pierced or damaged insulation can allow moisture to enter the wiring. The conductor can corrode inside the insulation with little visible evidence. Look for swollen and/or brittle sections of wire in the suspect circuits.
     
    Inspect for wires that are broken inside the insulation by gently pulling on suspect sections of wiring.
     

  4.  

Related Diagnostic Trouble Codes

Specific to:

Chevrolet Silverado 1500 2008



Click image to see an enlarged view

Fig. Related Diagnostic Trouble Codes

 
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