Ignition 1 voltage is supplied to the ignition coil. The engine control module (ECM) provides a ground for the ignition coil (IC) control circuits. When the ECM removes the ground path of the ignition primary coil, the magnetic field produced by the coil collapses. The collapsing magnetic field produces a voltage in the secondary coil which ignites the spark plugs. The sequencing and timing are controlled by the ECM.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Description and Operation:

Electronic Ignition (EI) System Description

Electrical Information Reference

Scan Tool Reference

Important: 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.

1. Ignition OFF, disconnect the harness connector at the ignition coil.
2. Ignition ON, load test for B+ between the ignition 1 voltage circuit of the ignition coil and ground.

⇒	If less than B+, test the ignition 1 voltage circuit for a short to ground or an open/high resistance.

3. Ignition OFF, test for less than 5 Ohms of resistance between the ground circuit of the ignition coil and ground .

⇒	If greater than 5 Ohms, test the ground circuit for an open/high resistance.

4. If all circuits test normal, replace the ignition coil.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Ignition Coil Replacement