Spark advance

Spark advance

The ECU processes the signals from the sensors and defines:

• - spark advance for each cylinder
• - spark delay for the required cylinder (according to knock).

Fan control

According to the coolant temperature, the ECU controls fan operation as follows:

• - 1^st speed at 95°C
• - 2^nd speed at 102°C.

If the climate control system is on, the ECU controls the fan at 1^st speed. Without the coolant temperature signal the ECU implements a recovery function by controlling the fan at 2^nd speed until the error is removed. Before starting the fans, the idling ratio is adapted by increasing the air delivery according to the fan to be started.

Idling ratio management

The ECU acknowledges idling condition when the accelerator pedal is released. The ECU controls idling speed by piloting the driven throttle according to the devices which are on and the signals from the brake-clutch pedals. When the fans are running at second speed, idling ratio goes from 700 to 750 rpm.

1. Fan control
2. Idling ratio management