Fiat Bravo Service Manual page 340

Engine
Fuel system
10.
NTC I N J E C T I O N
°C
a
-20 15970 40 1150
-10 9 6 2 0 50 807
0 5975 60 576
10 3816 70 418
20 309
2 5 0 0 80
25 231
2 0 4 4 90
100 176
30 1679
Connection to the coolant temperature gauge
in the Instrument panel
34
NTC
I N S T R U M E N T
°C
Q £2
60 512¬
90 184¬
120 7 6 -
C O O L A N T T E M P E R A T U R E S E N S O R
(Jaeger 402.183.01)
(Elth 2690350)
The sensor is fitted on the themostat casing;
it is made up of a brass casing w h i c h acts as
protection against the actual resistive ele-
ments made up of t w o NTC thermistors
(Negative Temperature Coefficient, where
the electrical resistance of the sensor de-
creases as the temperature increases). The
t w o NTCs are distinct and provide tempera-
ture information to the specific gauge in the
Instrument panel and to the injection/igni-
tion control unit. The reference voltage for
the NTC element for the injection system is 5
Volt; since the control unit inlet circuit is de-
signed as a voltage divider, this voltage is
shared between a resistance in the control
unit and the sensor NTC resistance. As a re-
sult, the control unit is capable of evaluating
the changes in voltage and obtaining temper-
ature information in this way.
1. NTC for injection system
2. NTC for gauge in Instrument panel
Recovery
The last value detected is taken as valid or a
fixed values of 80 °C if the temperature of the
intake air is above a given level. The self-ad-
justment of the mixture strength is inhibited.
The radiator fan is activated. The self-adjust-
ment of the idle is inhibited.
Checking the resistance
The table at the side contains the resistance
values w h i c h the NTC elements can assume
according to the temperature. These values
can be measured by by disconnecting the
connector and connecting an ohmmeter to
sensor pins.
Removing-refitting
Disconnect the electrical connection and re-
move the sensor
E
Tightening torque 2.2 da Nm.
Wiring connector
The numbers indicate the respective control
unit pins
Bravo ft 20v
98 range
Print no. 506.670/16