Procedure For Checking The Levelling System

• 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.

Information 

Do not get into or out of the vehicle while adjusting the vehicle to normal level and after adjusting it to normal level (do not change the position of doors and flaps). This can give false alignment results.

Perform check under the following 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 Only for vehicles with air suspension:  Switch to Normal Level and deactivate the levelling system.
   1. 1.1.1 Switch on the ignition.
   2. 1.1.2 Switch to Normal Level.
   3. 1.1.3 Press and hold the levelling system button until the message >>Levelling system switched off<< appears on the instrument cluster. > Levelling system button 

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.

   Levelling system button

2. 1.2 Compress the vehicle by approx. 25 mm at the front and rear axles 2-3 times and allow it to spring back freely.
3. 1.3 > VAS 6918 - Quick-Clamping Unit  must be fitted on the wheels.
   1. 1.3.1 Remove hub cap using > 9229/1 - pull-off hook  .
   2. 1.3.2 Mounting surfaces for the quick-clamping holders on the wheels and the adapter surfaces must be clean and flat.
   3. 1.3.3 Position quick-clamping unit with the claws first in the centre of the rim and clamp it in the rim by turning the retainer clockwise.
4. 1.4 Determine the actual value for the height of the vehicle body at the measuring points.

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.

   Dimension = upper edge of measured-value pickup to lower edge of wing, shown as an example

   1. 1.4.1 When determining the height of the vehicle body, measure the height from the lower edge of the wing to the upper edge of the measured-value pickup - dimension -X-  .
   2. 1.4.2 To this measured dimension -X-  , add the radius of the measured-value pickup 32.5 mm  .

      Sample calculation: 

      Measured dimension X = 382 mm; measured-value pickup radius = 32.5 mm

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

      382 mm + 32.5 mm = 414.5 mm

5. 1.5 Measure the vehicle height (See  ) 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 bellows 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 bellows
• Valve unit

If the shock absorbers are faulty, oil from the shock absorber 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.