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.





- Ignition on (positive and ground present at the high pressure sensor (G65))

- Oscilloscope settings: 5V / Div. = (5V per unit DC voltage) 5 ms / Div. (5 milliseconds per unit)

- Measuring lead (signal wire) connected to jack "7" of the test box (V.A.G 1598A) (with adapter cable (V.A.G 1598/12)).

- 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 -.