Air conditioning system control

AIR CONDITIONING SYSTEM CONTROL

When the air conditioner is turned on, the compressor absorbs power from the engine, which tends to stall when only idling. The control unit activates the fast idle function described previously to prevent this problem occurring.

The control unit also deactivates the compressor if one of the following conditions occurs:

1. Coolant temperature greater than 110 °C.
2. A given rpm threshold is exceeded (about 4500).
3. High engine power demand (high acceleration).

Under conditions 1 and 2 the compressor is reactivated when coolant temperature or rpm drop below the intervention threshold.

Under condition 3, power is cut off only temporarily and automatically restored after a few seconds even if the power requirement is still high.

Injector with controls

The injector with controls informs the electronic control unit of the true injection advance (beginning of injection stage, i.e. when the needle valve begins to move).

On the basis of the signal, the control unit corrects the advance set by the injector actuator until the rated value is reachede.

The injector is fitted to cylinder (1) and equipped with a device to identify the exact moment at which the injection stage begins and wiring to send a signal to the electronic control unit.

The injector contains a coil (2), a needle valve (3) and an adjustment pin (1). The coil is electrically activated and generates a magnetic flow which affects the needle valve (3). When the needle valve begins to open the nozzle for fuel injection, the magnetic flow alters in coil (2). The control unit identifies this as the moment when injection begins and bases its advance adjustment strategy on this reading.