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Intake air temperature sensor

Intake air temperature sensor





The temperature sensor is located in the intake manifold and is NTC type. The control module measures the air temperature in the intake manifold by supplying the sensor with 5V from pin 15 through a 2.74 kohm resistor integrated in the control module. The sensor is grounded from pin 70. The voltage across the resistor in the control module is proportional to the intake air temperature.

The temperature is used to:


Determine the density of the charge air together with charge air pressure. The charge air density is used by the air mass control to correct the throttle angle.

Correct the PWM ratio of the charge air control valve. A higher PWM ratio is required at high temperatures to obtain the same air mass/combustion.

Correct the ignition timing. A more advanced ignition is required at low temperatures.

Blocking certain diagnoses:

- Blocking certain diagnoses at temperatures lower than -7°C.

- Reactivate certain diagnoses at temperatures higher than 5°C.


Diagnostics


If the sensor voltage is too low, diagnostic trouble code P0112 will be generated.

If the sensor voltage is too high, diagnostic trouble code P0113 will be generated.

The control module sets a substitute value of 40°C.


System reaction to a fault


Density compensation of the throttle angle is blocked.