DISTRIBUTORLESS Ignition System: GX470
WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2003 Lexus SC 430, 2003 Lexus RX 300, 2003 Lexus LX 470, 2003 Lexus LS 430, and 2003 Lexus IS 300. However, it is still accessible from the selected car via links, so may be relevant.
Direct Ignition System is a one cylinder ignition system which ignites one cylinder with one ignition coil. Spark plug is connected to end of secondary winding. High voltage generated in secondary winding is applied directly to spark plug. ECM determines ignition timing and outputs ignition signals for each cylinder. Based on system sensor signals, power transistors in igniter cut off current to primary coil in ignition coil that is supplied to spark plug connected to end of secondary coil. Igniter also sends an ignition confirmation signal (IGF) as a fail-safe measure to ECM.