Component Description

RDC Control Unit 

Fully diagnosis-compatible

Task: 

Evaluates the following telegrams from the wheel electronic units:

• Tyre Pressure
• Tyre Air Temperature
• Identification Number Of Wheel Electronic Unit
• Remaining Service Life Of Wheel Electronic Unit Battery

Fig 1: Identifying RDC Control Unit

Courtesy of BMW OF NORTH AMERICA, INC.

If required, information or a warning is transmitted.

Wheel Electronic Unit With Valve 

Components:

• Pressure Sensor
• Temperature Sensor
• Transmitter
  • Frequencies According To Country
• Power Supply
  • Service Life: Approx. 7 Years
  • Not Exchangeable

Fig 2: Identifying Wheel Electronic Unit With Valve

Courtesy of BMW OF NORTH AMERICA, INC.

Installation Location Of Wheel Electronic Unit In Disc Wheel 

The wheel electronic unit (1) is screwed to the valve (2) on the disc wheel (3)

Identifying feature:  Metal Tyre Valves

Fig 3: Identifying Installed Position Of Wheel Electronic Unit In Disc Wheel

Courtesy of BMW OF NORTH AMERICA, INC.

Antenna 

There is an antenna in each wheel housing.

Task:  Receives telegrams and forwards these to the RDC control unit.

Fig 4: Identifying RDC Antenna

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Set Button 

Installed in the instrument panel to the right of the steering wheel. (E46: in the center console)

Symbol: tire cross-section

Task:  initialization after resetting cold tire pressure or after changing tire or wheel location.

Fig 1: Identifying RDC Set Button

Courtesy of BMW OF NORTH AMERICA, INC.

Display Element In Instrument Cluster 

Indicator lamp lights up yellow:

• drop in tire pressure of 0.2 to 0.4 bar

Indicator lamp lights up red:

• drop in tire pressure of greater than 0.4 bar

Fig 2: Identifying RDC Indicator In Instrument Cluster Display

Courtesy of BMW OF NORTH AMERICA, INC.