LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 1850 (Engine Controls And Fuel - 2.4L (Lat) - Troubleshooting & Diagnosis) >> Electronic Ignition (EI) System Diagnosis >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
    IMPORTANT: All electrical components and accessories must be turned OFF, and allowed to power down.
  1. Ignition OFF, disconnect the ignition coil/module harness connector at the affected ignition coil/modules.
  2. Ignition OFF, test for less than 5 ohms of resistance between the ground circuit terminal 1 and ground.
    • If greater than the specified value, test the ground circuit for an open/high resistance.
  3. Ignition OFF, test for less than 5 ohms of resistance between the low reference circuit terminal 2 and ground.
    • If greater than the specified value, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
    4. IMPORTANT: If the ignition fuse is open, it will be necessary to test the spliced ignition circuits and the components for a short to ground.
  4. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 4 and ground.
    • If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
  5. Exchange the affected ignition coil/module with the ignition coil/module of a good cylinder.
  6. Start the engine, observe the scan tool Misfire Current Cylinder parameters.
    • If the misfire transfers with the suspect ignition coil/module, replace as needed.
    • If the misfire does not transfer with the suspect ignition coil/module, refer to the Component Testing  procedures, and replace the spark plug if necessary.
scientia non olet · About LEMON Manuals