Intake air temperature sensor
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Intake air temperature sensor
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This temperature sensor is of the NTC type and is mounted in the intake manifold. The control module measures the air temperature in the intake manifold by supplying the sensor with 5V from pin 15 via an integral 2.74 Ohm resistor. The sensor is grounded via pin 22. The voltage across the resistor in the control module is proportional to the temperature of the intake air.
The temperature is used to:
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Determine, together with the charge air pressure, the density of the charge air. The charge air density is used by the air mass control system to correct the throttle angle.
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Correct the PWM ratio of the charge air control valve. At high temperatures, a higher PWM ratio is required to obtain the same air mass/combustion.
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Correct the ignition timing. At low temperatures, more advanced ignition is required.
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Block the OBD II diagnostics at starting temperatures below -7 °C.
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If the sensor voltage is too low, diagnostic trouble code P0112 will be generated.
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If the sensor voltage is too high, trouble code P0113 will be generated.
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The control module sets 40 °C as the substitute value.
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System reaction to a fault
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Density compensation of the throttle angle is blocked.
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