Ignition System: Testing and Inspection

ELECTRONIC IGNITION (EI) SYSTEM DIAGNOSIS

CIRCUIT DESCRIPTION
There are three dual-tower ignition coils that are part of the ignition control module (ICM). The ICM contains coil driver circuits that command the coils to operate. The ICM has the following circuits:
- An ignition voltage circuit
- A ground
- An IC 1 control circuit for the 1-4 ignition coil
- An IC 2 control circuit for the 2-5 ignition coil
- An IC 3 control circuit for the 3-6 ignition coil
- A low reference circuit

The powertrain control module (PCM) controls each dual-tower ignition coil by transmitting timing pulses on the IC control circuit to the ICM for the proper coil to enable a spark event.

TEST

Steps 1 - 5:

Step 6:

Steps 7 - 9:

Steps 10 - 15:

Steps 16 - 23: