Component description

WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2014 BMW X6, 2013 BMW X6, 2012 BMW X6, 2011 BMW X6, and 2010 BMW X6. However, it is still accessible from the selected car via links, so may be relevant.

RDC control unit

Fully diagnosis-compatible

Task:

evaluates the following telegrams from the wheel electronic units:

tire pressure
tire air temperature
identification number (ID) of wheel electronic unit
remaining service life of wheel electronic unit battery

If required, information or a warning is transmitted.

Fig 1: Identifying Wheel Electronic Unit Number

Courtesy of BMW OF NORTH AMERICA, INC.

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 tire valves

NOTE: Different valves have to be used to allow for the different disc wheel sizes. The valves are color-coded. The correct coding can be taken from the spare parts catalogue.

Fig 3: Identifying Wheel Electronic Unit Valve And 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 Antenna

Courtesy of BMW OF NORTH AMERICA, INC.

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: Locating 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 greater than 0.4 bar

Fig 2: Identifying Indicator Lamp Lights
Courtesy of BMW OF NORTH AMERICA, INC.

RDW control unit

Fully diagnosis-compatible

Task:

evaluates wheel speeds.
a warning is transmitted as required.

Fig 1: Identifying RDW Control Unit
Courtesy of BMW OF NORTH AMERICA, INC.

Set button

Installed in the dashboard to the right of the steering wheel. Symbol: tire cross-section with warning triangle

Task:

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

Fig 2: Locating Steering Wheel Set Button

Courtesy of BMW OF NORTH AMERICA, INC.

Display element in instrument cluster

Indicator lamp lights up red:

drop in tire pressure 30 ± 10 %

Fig 3: Locating Indicator Lamp Lights
Courtesy of BMW OF NORTH AMERICA, INC.