RS 4 Quattro Sedan V8-4.2L (BNS) (2007)
High Pressure Sensor / Switch: Testing and Inspection
High Pressure Sensor, Checking Pressure Signal
This image is displayed on the oscilloscope screen when the following basic conditions are met.
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Ignition on (positive and ground present at the high pressure sensor (G65))
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Oscilloscope settings: 5V / Div. = (5V per unit DC voltage) 5 ms / Div. (5 milliseconds per unit)
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Measuring lead (signal wire) connected to jack "7" of the test box (V.A.G 1598A) (with adapter cable (V.A.G 1598/12)).
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Measuring lead (shielding) connected to jack "14" (ground) of the test box (V.A.G 1598A) (with adapter cable (V.A.G 1598/12)).
‹› The display shows a signal that is transferred when the pressure in the refrigerant circuit is approximately 7 bar, it corresponds to an approximate
duty cycle of 25% (with compressor not engaged, an ambient temperature of 30 °C and properly filled refrigerant circuit).
‹› The impulse width - A - depends on the pressure in the refrigerant circuit (if pressure increases, area - A - gets wider).
‹› The signal distance - B - is always 20 milliseconds (corresponds to frequency of 50 Hertz).
‹› The duty cycle is determined by the ratio of impulse width - A - and signal distance - B -.