Checking Vehicle Height

Information 

• Only measure and adjust vehicles with air suspension in the Normal Level vehicle setting with narrow control tolerances. 
• Do not get into or out of the vehicle while or after setting the suspension measurement level. This can give false alignment results. 
• If the control unit or one of the level sensors was replaced, level control must be calibrated beforehand. 

  > WM, 430115 CALIBRATING THE LEVELLING SYSTEM

1. Only for vehicles with air suspension:  Switch to Normal Level with narrow control tolerances and deactivate level control.
   1. 1.1 PIWIS Tester  can now be connected.
   2. 1.2 Switch on the ignition and start Diagnosis.
   3. 1.3 Switch to Normal Level with narrow control tolerances menu item: → PASM/Measurement → Maintenance/repairs → Switch to Normal Level with narrow control tolerances. 
   4. 1.4 Deactivate the level control. 
2. Compress the vehicle by about 25 mm at the front and rear axles 2-3 times and allow it to spring back freely.
3. Determine the actual value for the height of the vehicle body at the measuring points.

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.

   Dimension X = upper edge of quick-clamping unit to lower edge of wing (shown as an example)

   1. 3.1 When determining the height of the vehicle body, measure the height from the lower edge of the wing to the upper edge of the quick-clamping unit, dimension -X-  .
   2. 3.2 Add the radius of the quick-clamping unit -X- 32.5 mm  to this measured dimension.

      Example calculation for rear axle: 

      Measured star gauge X= 386.5 mm (15.2 in.); radius quick clamping unit = 32.5 mm (1.27 in.)

      X  + radius of quick-clamping unit  = vehicle body height 

      386.5 mm (15.2 in.) + 32.5 mm (1.27 in.) = 419 mm (16.5 in.)

4. Only for vehicles with air suspension:  As soon as at least one of the measured height values does not correspond to the required height values, the level control must be calibrated.

   Required height values:

   > WM, 4495TW ADJUSTMENT VALUES FOR SUSPENSION ALIGNMENT 

   Calibrate the level control:

   > WM, 430115 CALIBRATING THE LEVELLING SYSTEM