Entering Wheel/Tire Combinations (APS)

NOTE: To enter wheel/tire combinations deviating from standard it is necessary to insert the APS test CD instead of the navigation CD vehicles with navigation processors (up to 11/96).

On vehicles with navigation processors (as of 12/96) the test software is stored in the operating unit. The wheel/tire combination can be stored with the aid of the user guided calibration program. For this reason only the displays for starting and entry are mentioned in the steps below.


Switch on radio and navigation operating unit APS (A2/29).

1. On vehicles up to approx. 11/96 insert test CD. Then make entries on APS operating unit.
2. On vehicles as of approx. 12/96 make entries on APS operating unit. For this purpose press keys AM and 4 within 20 s.







NOTE: The program points are run through with menu guidance.


NOTE: The calibrating path should be as straight as possible. The exact length must be known. Measure track (A) from center of wheel to center of wheel.

Enter the following on the APS operating unit


Operation Function
Select "SERVICE SW" in menu. Confirm by pressing volume knob (14).

Continue program up to next menu display
"SELECT VEHICLE MODEL".

Select menu point "MODIFIED CHASSIS". Confirm by pressing volume knob (14).

Continue program up to display
"TRACK IN MM".

Enter measured track. Measure track from center of wheel to center of wheel.
Select numbers for entry with cursor key (11) then confirm value entered by pressing volume knob (14) and holding down (approx. 4 s).

Continue program up to next display in menu
"DETERMINE TIRE VALUES".

Select menu point "OTHER TYPE OF TIRE". Confirm by pressing volume knob.

Continue program up to display Enter length of calibration path in m.
"LENGTH OF CALIBRATION PATH" The calibration path should be
> 100 m and straight, the longer the path, the more accurate the calibration.
Select numbers for entry with cursor key (11) and then confirm value entered by pressing the volume knob (14) and holding down (approx. 4 s).

Continue program up to display If an error message appears in the display after driving along the
"PLEASE SELECT" calibration path, check the wheel pulses.

After entering the wheel/tire combination Confirm by pressing volume knob (14). Insert navigation
select menu point "START NAVIGATION 100". CD and start system