Avalanche, Sierra, Silverado, C&K Series, 1999-2005

Testing

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  1. Turn the ignition switch to ON , but do not start the engine.
  2.  
  3. Disconnect the sensor lead at the sensor. Connect a test lamp to the lead; The lamp should glow. If not, check the wiring, fuses and connections.
  4.  
  5. Disconnect the test lamp and ground the connector. The gauge should read at the HOT mark.
  6.  
  7. Remove the connector from ground. The gauge should read at the COLD mark.
  8.  
  9. At 104°F (40°C) the resistance of the sensor should be 1365 ohms.
  10.  
  11. At 257°F (125°C) the resistance of the sensor should be 55 ohms.
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CAUTION
To avoid being burned, do not remove the radiator cap or surge tank cap while the engine is hot. The cooling system will release scalding fluid and steam under pressure if radiator cap or surge tank cap is removed while the engine and radiator are still hot.


NOTE
Use care when handling the coolant sensor. Damage to the coolant sensor will affect the operation of the fuel control system.


NOTE
Replacement components must be the correct part number for the application. Components requiring the use of the thread locking compound, lubricants, corrosion inhibitors, or sealants are identified in the service procedure. Some replacement components may come with these coatings already applied. Do not use these coatings on components unless specified. These coatings can affect the final torque, which may affect the operation of the component. Use the correct torque specification when installing components in order to avoid damage.

  1. Remove the ECT sensor.
  2.  
  3. Measure and record the resistance of the ECT sensor at various temperatures, then compare those measurements to the following. The change in resistance should occur smoothly. If there are any sudden changes, the sensor is faulty.

    -4°F: 28680 ohms
     
    14°F: 16180 ohms
     
    32°F: 9420 ohms
     
    50°F: 5670 ohms
     
    68°F: 3520 ohms
     
    86°F: 2238 ohms
     
    104°F: 1459 ohms
     
    122°F: 973 ohms
     
    158°F: 467 ohms
     
    194°F: 241 ohms
     
    230°F: 132 ohms
     
    266°F: 77 ohms
     

  4.  
  5. If the sensor tests outside of these ranges, replace the sensor.
  6.  

  1. Remove the ECT sensor.
  2.  
  3. Measure and record the resistance of the ECT sensor at various temperatures, then compare those measurements to the following. The change in resistance should occur smoothly. If there are any sudden changes, the sensor is faulty.

    -4°F: 28680 ohms
     
    14°F: 16180 ohms
     
    32°F: 9420 ohms
     
    50°F: 5670 ohms
     
    68°F: 3520 ohms
     
    86°F: 2238 ohms
     
    104°F: 1459 ohms
     
    122°F: 973 ohms
     
    158°F: 467 ohms
     
    194°F: 241 ohms
     
    230°F: 132 ohms
     
    266°F: 77 ohms
     

  4.  
  5. If the sensor tests outside of these ranges, replace the sensor.
  6.  

 
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