Procedure for checking the levelling system

1. Perform the following check under these conditions:
   • The vehicle must be standing on a level surface.
   • The vehicle must be cold and must not be moved during the check.
   • The room temperature should be between 10°C and 30°C and must not fluctuate to any great extent.
   1. 1.1. Adjust the vehicle to Normal Level.
      1. 1.1.1. Stop the engine and move selector lever to position P.
      2. 1.1.2. PIWIS Tester II 9818  must now be connected.

         Do not get into or out of the vehicle while adjusting the vehicle to normal level and after adjusting it to normal level. This can give false alignment results  .

      3. 1.1.3. Select >>Levelling system/PASM<<>>Drive links/checks<<>>Adjust vehicle level<< in the control unit overview.
      4. 1.1.4. Select the value Low level 1  and press [F8] to start. Vehicle adjusts to Low Level.
      5. 1.1.5. Once Low Level has been reached, select Normal Level  and press [F8] to start. Vehicle now adjusts to Normal Level.
   2. 1.2. Switch off the levelling system (switch it back on again when work is complete).
      1. 1.2.1. Use PIWIS Tester II 9818  to select >>Levelling system/PASM<<>>Drive links/checks<<>>Activate/deactivate vehicle<< in the control unit overview.
      2. 1.2.2. Select the value Deactivate levelling system (permanently)  and press [F8] to start. The levelling system is now switched off.
   3. 1.3. Compress vehicle at front and rear axles by approximately 25 mm 2-3 times and allow it to spring back freely.
   4. 1.4. Open the bonnet.
   5. 1.5. Fit measured-value pickup Quick clamping device WE 1621  on the relevant wheel.

      Information 

      Check the following at the height measuring point on the front axle: 

      • Lower edge of the wing is covered by the front lid  .
      • Only measure the height on the front axle when the front lid is open  .
   6. 1.6. Determine the actual value for the height of the vehicle body at the measuring points.

      Courtesy of PORSCHE CARS NORTH AMERICA, INC.

      1. 1.6.1. When determining the height of the vehicle body, the height is measured from the lower edge of the wing to the upper edge of the measured-value pickup, dimension X  .
      2. 1.6.2. Then add the radius  of the measured-value pickup 32.5 mm  to this measured dimension X.

         Sample calculation: 

         Measured dimension X = 430 mm; measured-value pickup radius = 32.5 mm

         X  + measured-value pickup radius  = height of vehicle body 

         430 mm + 32.5 mm = 462.5 mm

   7. 1.7. Measure the vehicle height (→ 1.6  .) again after two hours and compare it with the first measurement.

      Dimensions and tolerances can be taken from the prescribed vehicle height for vehicles with air suspension. → 4495TW ADJUSTMENT VALUES FOR SUSPENSION ALIGNMENT

   If the vehicle is lying at an angle, there is a leak at the wheel suspension with the greatest difference between the first and second measurement.

   Use commercially available leak detection spray to check the affected air-spring strut/air spring and the relevant air line one after the other.

   If there is no difference after two hours, the vehicle height must be measured again after 24 hours.

   The following components must also be checked:

   • Air line connections
   • Air-spring strut/air spring
   • Valve unit

   If the vibration dampers are faulty, oil from the vibration damper may have entered the air supply system. To ensure that the air spring system works perfectly, it is absolutely essential that you clean the system after a fault is found and replace other components.

2. Procedure for repairing the air spring system after a fault is found on the vibration dampers:

• Screw off the affected line on the air-spring strut/air spring and solenoid valve block.
• Blow out the line several times until it is clean using compressed air by introducing the compressed air at the end of the line at the solenoid valve block.
• Check for traces of vibration damper oil in the solenoid valve block.
• If vibration damper oil has contaminated the valve unit, it must be replaced.
• Check the internal line from the compressor to the solenoid valve block.
• If there is oil in the line between the compressor and the pressure accumulator, the line and the pressure accumulator must be replaced.

If there is oil in the internal line, the compressor must be replaced.