Circuit Description
WARNING: This page is about a different car, the 2002 Lexus ES 300. However, it is still accessible from the selected car via links, so may be relevant.
ECM determines ignition timing and outputs ignition signals (IGT) for each cylinder. Based on IGT signals, power transistors in ignitor cuts off current to primary coil in ignition coil is supplied to spark plug that are connected to end of secondary coil. At same time, ignitor also sends an ignition confirmation signal (IGF) as a fail-safe measure to the ECM. Possible causes are:
- IGF or IGT circuit from ignitor to ECM is open or shorted.
- Defective ignitor.
- Defective ECM.