System activation button, component description - GF40.15-P-5127TR

MODEL 211 as of 1.6.05

with CODE (475) Tire pressure monitor (Siemens)

except CODE (494) USA version

except CODE (498) Japan version

MODEL 211 as of 1.7.05

with CODE (475) Tire pressure monitor (Siemens)

with CODE (494) USA version

with CODE (498) Japan version

MODEL 211

with CODE (470) Tire pressure monitor (base)

with CODE (494) USA version

Fig 1: Identifying Steering Wheel Buttons

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Task

The TPM system is permanently operational and is not actively operated by the driver. Each time CAN B is awoken (starting procedure or ignition "ON") the TPM [RDK] control unit (N88) starts a reinitialization and starts to send messages to the instrument cluster (A1). A new activation of the TPM system can be triggered via the scroll forward/back button and button + and -, setting of specific functions and volume controls as well as the instrument illumination rheostat and reset button (A1r1) on the instrument cluster.

The TPM system can be reactivated in the following cases:

The tire pressure has been changed (e.g. after refilling).
After each wheel/tire change
After fitting new wheels or tires

When the TPM system is activated, the air pressure values of the wheels set by the driver are stored as specified monitoring data in the TPM [RDK] control unit.