Fiat 1996 Brava Service Manual page 590

Bravo-Brava
98 range
Auxiliary units
Manually operated climate control
50.
OPERATION OF THE COMPRESSOR ELECTRONIC CONTROL UNIT
The system for activating/deactivating the compressor is operated by an electronic control unit (elec­
tronic thermostat) (3), which acts on the compressor clutch according to the temperature of the evapo­
rator, measured by an N.T.C. type sensor (2).
If the temperature of the evaporator reaches values below 3.5 °C, the electronic unit releases the c o m ­
pressor coupling relay and consequently the compressor coupling.
The compressor coupling is disengaged if the driver accelerates fully and when the engine temperature
reaches 107 °C, to prevent overheating. These control operations are carried out by the fuel injection
control unit.
+ 15 INT/A , ' ' / V \
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1. Air conditioning on switch
2. Air temperature sensor on the evaporator
3. Compressor electronic control unit (elec­
tronic thermostat)
4. Four stage pressure switch
Air temperature sensor on the evaporator
The temperature sensor is an N.T.C. resistance and is kept in place, by means of a retaining spring, on the
evaporator fins, on the downstream side of the air f l o w and is not accessible from the outside.
The control unit w h i c h deactivates the compressor according to the temperature of the air measured at
the evaporator outlet is calibrated as follows:
ON
DFF
4
„
A
3,5±0,5°C
k
5,0 ± 0,5 °C
P4A19CH02
In particular, the control unit activates the coupling when the temperature of the air exceeds 5.0 ± 0 . 5 °C
and deactivates it w h e n the temperature goes below 3.5 ±0.5 °C.
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