Checking pressure signal from High Pressure Sensor G65
WARNING: This page is about a different car, the 2008 Audi S4, 2008 Audi RS 4, and 2008 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.
This display appears on the oscilloscope screen if the following conditions are fulfilled.
- Ignition switched on (positive and Ground (GND) applied to High Pressure Sensor G65)
- Oscilloscope settings: 5 V/div. DC (5 V per unit DC voltage) 5 ms/div. (5 milliseconds per unit)
- Measuring lead (signal wire) connected to socket "7" of Test Box V.A.G 1598A (with Adapter - 16 Terminals V.A.G 1598/12)
- Measuring wire (screen) connected to socket "14" (Ground (GND)) of Test Box V.A.G 1598A (with Adapter - 16 Terminals V.A.G 1598/12)
NOTE:
- The illustration shows the signal transmitted at a refrigerant circuit pressure of approx. 7 bar absolute, corresponding to a duty cycle of approx. 25% (level occurring with compressor not running, ambient temperature of 30 °C and refrigerant circuit charged).
- The pulse width - A - is governed by the pressure in the refrigerant circuit (area - A - becomes broader as pressure increases).
- The signal distance - B - is always 20 milliseconds (corresponding to a frequency of 50 Hertz).
- The duty cycle is derived from the ratio of pulse width - A - to signal distance - B -.