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Intake air temperature

Intake air temperature



Air temperature

The control module receives information on the temperature of the intake air from the temperature sensor. The resistance of the sensor, which is of NTC type, varies with the temperature and therefore so does the voltage level on pin 44 of the control module.

The way in which resistance and voltage are dependent on temperature is shown in the table below:

°C

°F

Voltage (approx.)

Resistance (approx. kilo-ohms)

-30

-22

4.8

20-30

-10

14

4.5

8.3-10.6

20

68

3.5

2.3-2.7

40

104

2.7

1.0-1.3

60

140

1.9

0.56-0.67

80

176

1.2

0.30-0.36



The control module does not normally need information from the intake air temperature sensor in order to determine the amount of fuel. In certain cases, however, such as when the intake air is abnormally hot and the engine is under heavy load, the control module uses this information to prevent knocking.

In the event of a break in the circuit, the control module selects a fixed value corresponding to an air temperature of 20°C.

The temperature sensor is connected to signal ground together with a number of other sensors via pin 30 of the control module.