Circuit Description

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

• IGF or IGT open or short circuit from ignitor to ECM.
• Ignitor.
• ECM.