Operation CHARM: Car repair manuals for everyone.

GF40.15-P-2005GZ Detection of Pressure Loss, Function



GF40.15-P-2005GZ Detection of pressure loss, function
- with CODE (477) Tire pressure loss warning






Warning message





Reminder message

Function
The ESP control unit (N47-5) compares the 4 wheel speeds depending on the tire pressure. A learning phase follows reactivation. In this phase in 6 different vehicle speed intervals the relative rolling circumferences of the tires are taught in and stored. The tire pressure loss warning (RDW) is not active during this learning process. The coordination of the individual intervals takes 10 minutes/interval. From this point onward the tires:
^ FL and RR,
^ RF and LR

are subjected to mutual comparisons.

Warning message
The tire pressure loss warning RDW has established while driving that the rolling circumferences of the wheels have changed relative to each other (considerable pressure loss in one tire).

Reminder message
This message is displayed in the multifunction display (A1p13) after a red warning message, if tire pressure loss warning is not subsequently reactivated.