Fiat 1998 Marea Weekend, Service Manual

Page: 228 / 846

Engine
Fuel system
16v
Marea- Marea Weekend ft
99 range
10.
MANAGEMENT OF THE RADIATOR FAN
NOTE Since the temperature of the coo/ant is measured by the sensor there is no longer a thermal con-
tact on the radiator.
The engine control unit controls the engagement of the radiator fan according to the temperature of the
coolant and whether or not there is a climate control system.
In the case of versions with climate control, there are two fan operating speeds, managed according to
two different, completely independent logics.
- According to the temperature of the coolant.
Low speed: it comes on when the temperature of the coolant reaches T 1 = 96.5 "C;
High speed: it comes on when the temperature of the coolant reaches T 2 = 102 °C.
It switches off with a hysteresis of around 3 °C.
- According to the four stage pressure switch condition.
Low speed: it switches on when level II of the pressure switch is engaged;
High speed: it switches on when level III of the pressure switch is engaged.
T 1 = 96.5 °C
T 2 = 102 °C
ON: pressure switch activated
OFF: pressure switch deactivated
1. Solenoid valve status 0 = off
1 = low speed
2 = high speed
2. level II of four stage pressure switch
3. level III of four stage pressure switch
4. Progress of engine coolant temperature
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