Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the affected T8 ignition coil/modules.
- Ignition OFF, all vehicle systems OFF. This may take up to 2 minutes. Test for less than 5 Ω between the ground circuit terminal A/1 and ground.
- If greater than the specified range, test the ground circuit for an open/high resistance.
- Test for less than 5 Ω between the low reference circuit terminal B/2 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 K20 ECM.
- Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal D/4 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 T8 ignition coil/module with the T8 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 T8 ignition coil/module, replace as needed.
- If the circuits test normal, test or replace the spark plug/s.