Pressure sensor, A/C (620), E39
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Pressure sensor, A/C (620), E39
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Fitted near the left front corner of the air filter.
Pressure sensor, A/C (620), E39
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The value is used by ECM, control module, E39 (590), for load compensation depending on the A/C compressor load of the engine. Also used for radiator fan logic and block conditions (pressure switch) in the A/C system.
The pressure sensor contains two metal plated ceramic discs mounted in close proximity. The disc located closest to the pressure connection is thinner and bends when subjected to pressure. By this means, capacitance between the metal plating of the discs is changed based on the pressure. A circuit integrated in the pressure sensor converts the capacitance to an analogue output voltage.
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620 pin no.
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Signal type
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Description
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1
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Ground
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Connected to ECM pin 22(A).
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2
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Power supply, 5 V
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Connected to ECM pin 21(A).
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3
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Signal
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Connected to ECM pin 6(A).
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The pressure sensor is secured to the A/C pipe on the high-pressure side. Based on the pressure in the intake manifold, the pressure sensor provides a proportional voltage to ECM, pin 6(A).
