Fiat 1996 Brava Service Manual page 340

Engine
Fuel system
10.
NTC INJECTION
NTC
INSTRUMENT
-20
-10
0
10
20
25
30
a
15970
9620
5975
3816
2500
2044
1679
°C
40
50
60
70
80
90
100
Q
1150
807
576
418
309
231
176
°C
60
90
120
Q
512-602
184-208
7 6 - 8 8
Bravo <§l 20v
98 range
COOLANT TEMPERATURE SENSOR
(Jaeger 402.183.01)
(Elth 2690350)
The sensor is fitted on the themostat casing;
it is made up of a brass casing which acts as
protection against the actual resistive ele­
ments made up of two NTC thermistors
(Negative Temperature Coefficient, where
the electrical resistance of the sensor de­
creases as the temperature increases). The
two 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 which 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.
Connection to the coolant temperature gauge
in the Instrument panel
Wiring connector
The numbers indicate the respective control
unit pins
34
Print no. 506.670/16