Circuit Description

The ECM determines ignition timing and outputs ignition signals (IGT) for each cylinder. Based on IGT signals, the igniter controls the primary ignition signals (IGC) for all ignition coils. The igniter also sends an ignition confirmation signal (IGF) as a fail-safe measure to ECM. DTC is set if ECM does not receive a IGF signal while engine is running. Possible causes are:

• IGF or IGT open or short circuit from igniter to ECM.
• Igniter.
• ECM.