Management Of The Radiator Fan - Fiat Bravo Service Manual

Engine
Fuel system
10.
M A N A G E M E N T OF T H E RADIATOR FAN
N O T E Since the coolant temperature is detected by the appropriate sensor there is no longer a thermal
contact on the radiator.
The engine control unit operates the engagement of the radiator fan according to the temperature of the
coolant andwhether or not there is a climate control system.
In the case of versions w i t h climate control, there are t w o fan operating speeds, managed according to
different logics, entirely independent of one another.
- According to the coolant temperature.
Low speed: this is switched on w h e n the temperature of the coolant reaches T i = 96.5 °C;
high speed: this is switched on when the temperature of the coolant reaches T2 = 102 °C.
The fan is switched off with a temperature hysteresis of around 3 °C.
- According to the condition of the four stage pressure switch.
Low speed: this is switched on when stage II of the pressure switch is triggered;
high speed: this is switched on when stage III of the pressure switch is reached.
Ti = 96.5 X
T2
= 102 °C
ON: pressure switch activated
OFF: pressure switch deactivated
14
1. Fan state.
2. Four stage pressure switch level II
3. Four stage pressure switch level III
4. Engine coolant temperature progress
Bravo-Brava & | 16v
98 range
0 = off
1 = l o w speed
2 = high speed
Print no. 506.670/76