Circuit/System Testing
- Ignition OFF, disconnect the harness connector of the ignition coil.
- Ignition ON, load test for battery voltage between the ignition 1 voltage circuit of the ignition coil and ground.
- If less than B+, repair the ignition 1 voltage circuit of the ignition coil for a short to ground or an open/high resistance.
- Measure the resistance between the ground circuit of the ignition coil and ground. Verify the resistance is less than 5 ohms.
- If greater than 5 ohms, repair the ground circuit of the ignition coil for an open/high resistance.
- Start the engine. Measure the frequency between the appropriate ignition control circuit and ground. Verify the frequency is more than 10 Hz.
- If less than 10 Hz, test the ignition control circuit for a short to voltage, short to ground or an open/high resistance. If the circuit/connection test normal, replace the ECM.
- If all circuits/connections test normal, replace the ignition coil.
IMPORTANT:
Set the DMM to the AC Hertz scale for this test.