Role and Functioning of the Intake Tube Pressure Sensor
The measured values of the manifold pressure sensor and therefore the intake air temperature sensor are required to calculate the intake atmosphere .
Depending on the injection system, the manifold pressure sensor and therefore the intake air temperature sensor are often fitted to the one-piece housing. The manifold pressure sensor are often mounted directly within the manifold or installed nearby.
Functioning
The sensitive a part of the pressure sensor may be a screen printed Wheatstone bridge on a diaphragm. this is often made from four resistors which are switched together during a closed ring with a Voltage Source on one diagonal and a Tensiometer on the opposite . there’s an atmospheric depression on one side of the diaphragm, on the opposite side of the intake tube depression. The signal resulting from the deformation of the diaphragm is ready by the analysis electronics and transmitted to the engine ECU.
In the resting state, the diaphragm bends consistent with the pressure of the surface air. The vacuum acts with the motor running on the diaphragm of the sensor in order that the resistance is affected. Since the reference voltage is completely constant (5 V), the output voltage changes in proportion to the change in resistance.
The sensor for the air temperature may be a CTN resistor (negative temperature coefficient). The resistance of the sensor decreases because the temperature rises.
The input circuit of the electronics distributes the reference voltage of 5 V between the resistance of the sensor and a hard and fast resistor in order that a voltage proportional to the resistance and thus to the temperature is obtained.
Connection diagram
Although externally it’s impossible to detect a difference from the intake pipe pressure sensor
current, another contact within the housing is noticed with a better observation of the mating connector.
On the 6PP 009 400-481 intake tube pressure sensor shown here within the graphic, this contact is identified with (t).
The CTN mounted within the sensor for temperature measurement is connected with the engine ECU via this contact, via the wire harness.
Connection diagram
– (+) Supply voltage
– ( – ) Mass
– (t) Temperature output / sensor
– (MAP) Pressure sensor output / signal
Sensor replacement
Replace manifold Absolute Pressure (MAP) Sensor – Dodge, Chrysler, Plymouth 2.7L
