The basic ignition advance angle is determined using the NE signal and the VG signal or PIM signal. The NE and VG signal data used to determine the basic ignition advance angle is stored in the engine ECU memory.
1. Control when the IDL signal is ON
When the IDL signal is ON, the ignition timing is advanced in accordance with the engine speed.
HINT:
In some engine models the basic ignition advance angle is changed depending on whether or not the air conditioner is ON or OFF. In addition, of these models, some have an advance angle of 0 during standard idling speed.
2. Control when the IDL signal is OFF
The ignition timing is determined in accordance with the NE signal and VG or PIM signal based on the data stored in the engine ECU. Depending on the model, two basic ignition advance angles are stored in the engine ECU. The data for one of these is used to determine the advance angle based on the fuel octane value, so the data that matches the fuel used by the driver can be selected. In addition, some models of vehicles with fuel octane judgment capability use the KNK signal to automatically change the data used to determine the ignition timing.