Fiat 1998 Marea Service Manual page 359

Engine
Fuel system
10.
B1
rl-f-I-
INJECTION NTC
Q °C
-20 15970 40
-10 9620 50
0 5975
60
10 3816 70
20
2500 80
25 2044 90
30 1679 100
Connection to the engine coolant temperature
gauge in the instrument panel
34
B2 A
INSTRU-
MENT
NTC
Q °C Q
1150 60 512-602
807 90 184-208
576
120 76-88
418
309
231
176
Marea- Marea Weekend fii
ENGINE COOLANT TEMPERATURE SEN-
SOR
(Jaeger 402.183.01)
(Elth 2690350)
This sensor is fitted on the thermostat casing;
it comprises a brass casing which affords pro-
tection to the actual resistive elements con-
sisting of two NTC (Negative Temperature Co-
efficient) type thermistors where the electrical
resistance of the sensor decreases as the tem-
perature increases. The two NTCs are distinct
and provide information concerning the tem-
perature to the specific gauge in the instrument
panel and to the injection/ignition control unit.
The reference voltage for the NTC element for
the injection system is 5 Volt becuse the con-
trol unit intake circuit is designed as a voltage
divider so this voltage is divided between a re-
sistance in the control unit and the sensor NTC
resistance. As a result the control unit is capa-
ble making evaluations through the changes in
the voltage and thereby obtain information
concerning the temperature.
1. Injection system NTC
2. Instrument panel gauge NTC
Recovery
The last value measured or a fixed value of 80
°C is used if the temperature of the intake air is
above a certain level. The self-adjustment of
the mixture strength is inhibited. The radiator
fan is activated. The self-adjustment of the idle
is inhibited.
Checking the resistance
The table at the side contains the resistance
values for the NTC elements depending on the
temperature. These values can be measured by
disconnecting the connector and connecting
an ohmmeter to the sensor pins.
Removing-refitting
Disconnect the electrical connection and re-
move the sensor.
E
Tightening torque 2.2 daNm.
Connector wiring
The numbers indicate the control unit pins.
99 range
Print n'506.763/14