IC Mode

Display shows PCM or ICM. In PCM mode, the PCM controls the ignition timing. The PCM calculates the desired ignition timing based on information the PCM receives from the input sensors. In Ignition Control Module (ICM) mode, the ignition system operates independently from the PCM. The Ignition Control Module maintains a base ignition timing of 10 degrees BTDC and is able to change this ignition timing slightly with increased engine speed. Ignition control mode is in affect whenever an ignition control fault is detected while the engine is running and it will have a noticeable effect on driveability.