Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the affected ignition coil/modules.
- Ignition OFF for 90 seconds, test for less than 5 ohms between the ground circuit terminal C and ground.
- If greater than the specified range, test the ground circuit for an open/high resistance.
- Test for less than 5 ohms between the low reference circuit terminal D and ground.
- If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
- Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal A and ground.
- If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
- Exchange the affected ignition coil/module with the ignition coil/module of a good cylinder.
- Start the engine, and observe the scan tool Misfire Current Cylinder parameters.
- If the misfire transfers with the suspect ignition coil/module, replace as needed.
- If the circuits test normal, test or replace the spark plug/s.
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.