Tire pressure monitor (TPM), displaying tire inflation pressure - GF40.15-P-0001-03B
Models 215, 220 up to 31.05.01
The tire pressure monitor system allows the driver to call up a display of the instantaneous actual pressures in the individual tires in the multifunction display (A1p13) when the vehicle is moving or while it is stationary with the ignition ON. The values displayed are the actual measured values without temperature compensation. Changes in the pressure displays while driving are due to changing temperatures of the air inside the tires.
Displaying tire inflation pressure:
- Starting from the standard display, press the
button twice or the
button twice on the multifunction steering wheel.
- The instantaneous actual pressures in the individual tires appear in the multifunction display (A1p13).
System message
Occasionally, a system message or a pressure display without numerical values may be displayed for a short time instead of the pressure values. This is the case when an activation sequence has been triggered, or when wheel sensors have recently been replaced or different wheels have been fitted. In these cases the tire pressure monitor system checks whether the locations of the wheels have changed. The pressure values are only displayed when the system has been able to match the signals to the wheels.
Pressure display without numerical values
By measuring the field strengths at the left front tire pressure monitor antenna (A2/44), the right front tire pressure monitor antenna (A2/45), the left rear tire pressure monitor antenna (A2/46) and the right rear tire pressure monitor antenna (A2/47), the system's logic circuits automatically detect the wheels with wheel electronics installed on the vehicle, and can identify their locations. If the wheel assignment changes (e.g. when changing a wheel), a learning process commences which can identify the new state after max. 30 min driving. This process is only active while driving in order to prevent incorrect assignments due to signals from other vehicles. Initially, the system message is displayed. This message is displayed until the transmitted signals are plausible again. The pressure display then appears without numerical values until the initialization sequence is complete.