Circuit/System Testing
- Ignition OFF, disconnect the harness connector of the ignition coil.
- Ignition ON, load test for battery voltage between the ignition voltage circuit terminal 2 and ground.
- If less than B+, test the ignition voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, test all the components connected to the ignition voltage circuit and replace as necessary.
- Crank or start the engine. Test for 200-400 mV between the appropriate IC circuit terminal 1 and ground.
- If less than the specified value, test the IC circuit for a short to ground or an open/high resistance. If the circuit/connection tests normal, replace the ECM.
- If greater than the specified value, test the IC circuit for a short to voltage. If the circuit/connection tests normal, replace the ECM.
- Connect a test lamp between the each of the ground circuits terminal 3, and terminal 4, and B+. The test lamp should illuminate on each circuit.
- If the test lamp does not illuminate, test the suspected circuit for an open/high resistance.
- If all circuits/connections test normal, replace the ignition coil.
NOTE:
Do not perform this diagnostic procedure if you were not sent here from a misfire DTC or the Engine Cranks but Does Not Run diagnostic.