Air Conditioning System Control; Injector With Controls - Fiat Bravo Service Manual

Engine
Fuel system
10.
Coolant
temperature
Rpm
Air conditioner
activation request
ECU
Battery voltage
i Atmospher-1
i
1
pressure
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).
10
Air
condi-
tioner
compres-
sor
ic 1
1
3 2 1
P4A08EJ02
Bravo-Brava 1 0
A I R CONDITIONING S Y S T E M C O N T R O L
When the air conditioner is turned on, the
compressor absorbs power from the engine,
w h i c h 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 c o m -
pressor if one of the following conditions oc-
curs:
1. Coolant temperature greater than 110 °C.
2. A given rpm threshold is exceeded (about
4500).
3. High engine power demand (high accel-
eration).
On the basis of the signal, the control unit
corrects the advance set by the injector actu-
ator until the rated value is reachede.
The injector is fitted to cylinder (1) and
equipped with a device to identify the exact
moment at w h i c h 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 mag-
netic flow w h i c h affects the needle valve (3).
When the needle valve begins to open the
nozzle for fuel injection, the magnetic f l o w
alters in coil ( 2 ) . The control unit identifies
this as the moment when injection begins
and bases its advance adjustment strategy on
this reading.
TD
Publication no. 506.670/06