Distributor Ignition (DI) System

Input/Output Signal Chart:

SYSTEM DESCRIPTION
The ignition timing is controlled by the PCM to maintain the best air-fuel ratio for every running condition of the engine. The ignition timing data is stored in the PCM. This data forms the map shown above. The PCM receives information such as the injection pulse width and camshaft position sensor (PHASE) signal. Computing this information, ignition signals are transmitted to the power transistor.

e.g., N: 1,800 rpm, Tp: 1.50 msec A °BTDC

During the following conditions, the ignition timing is revised by the PCM according to the other data stored in the PCM.
- At starting
- During warm-up
- At idle
- At low battery voltage
- During acceleration

The knock sensor retard system is designed only for emergencies. The basic ignition timing is programmed within the anti-knocking zone, if recommended fuel is used under dry conditions. The retard system does not operate under normal driving conditions.

If engine knocking occurs, the knock sensor monitors the condition. The signal is transmitted to the PCM. The PCM retards the ignition timing to eliminate the knocking condition.