Circuit Description
WARNING: This page is about a different car, the 2002 Lexus LX 470. However, it is still accessible from the selected car via links, so may be relevant.
Direct Ignition System (DIS) is a 1-cylinder ignition system that ignites one cylinder with one ignition coil. Ignitor is integral to ignition coil. ECM determines ignition timing and outputs an ignition signal (IGT) for each cylinder. Based on IGT signals, power transistors in ignitor cut off current to primary coil in ignition coil, causing ignition coil to fire spark plug. After delivering a command to turn off primary circuit on IGT wire, ECM monitors IGF circuit to ensure primary switching occurred. DTC is set when there is no IGF signal to ECM during engine operation. Possible causes are:
- IGF or IGT circuit from ignitor to ECM is open or shorted.
- Defective ignition coil/ignitor.
- Defective ECM.