Silverado 2008

Diagnosis & Testing

Print

4.3L Engines



Circuit

Specific to:

Chevrolet Silverado 1500 2008

  1. With the ignition OFF, remove the fuel pump relay.
  2.  
  3. Crank the engine and test for spark at each spark plug wire, using tool J-26792 or equivalent. Follow tool manufacturer-s instructions.
  4.  
  5. If a bright blue spark is present on all cylinders remove and inspect the spark plugs. Replace plugs as required.
  6.  
  7. If there is no spark on any cylinders, test the ignition voltage circuit of the ICM for an open/high resistance or short to ground, or test the ground circuit of the ICM for an open/high resistance, or a faulty ICM. The wire circuit resistance should measure less than 3 ohms.
  8.  
  9. If spark is present on one or more of the cylinders, inspect and test the spark plug wires for arching, cuts, rubbing and proper resistance. Replace as required.
  10.  
  11. If all tests are normal, the system is operating correctly.
  12.  

Component

Specific to:

Chevrolet Silverado 1500 2008

  1. With positive polarity to the low reference terminal, measure for 9000 to 11000 ohms at 68 to 74 degrees, between each of the ignition coil control terminals and the low reference terminal of the ICM.
  2.  
  3. If resistance is not within specification, replace the ICM.
  4.  
  5. Measure for 7000 to 15000 ohms at 68 to 74 degrees between each pair of coil towers on the ICM.
  6.  
  7. If resistance is not within specification, replace the ICM.
  8.  

4.8L, 5.3L And 6.0L Engines



This ignition system uses individual ignition module/coil assemblies for each cylinder. The ECM controls the spark events by transmitting the timing pulses on the ignition coil (IC) circuits to each of the individual ignition module/coil assemblies in firing order sequence.

 
label.common.footer.alt.autozoneLogo