Tyre Pressure Monitor TPM
Principle The system monitors the tyre pressure in the
four fitted tyres. The system warns if the infla‐
tion pressure in one or more tyres has fallen
considerably. To do this, the sensors in the
tyre valves measure the tyre pressure and tyre
temperatures.
Note
To operate the system, also follow the other
information and notes under tyre inflation pres‐
sure, see page 175.
Operating requirements For the system, a reset must have been made
with the correct tyre inflation pressure, other‐
wise reliable signalling of a flat tyre cannot be assured.
Reset the system after adjusting the tyre pres‐
sure to a new value and after a tyre or wheel
change.
Always use wheels with TPM electronics to
guarantee the system functions without errors.
Status display
The current status of the Tyre Pressure Moni‐
tor TPM can be shown on the Control Display,
for example whether the TPM is active.
On the Control Display:1."Vehicle information"2."Vehicle status"3. "Tyre Pressure Monitor (RDC)"
The status is displayed.
Status control display The tyre and system status is denoted by the
wheel colour and some text on the Control Dis‐
play.
All wheels green
System is active and is warning about the tyre
inflation pressures stored during the last reset.
One wheel yellow
A flat tyre or major loss of tyre inflation pres‐
sure in the tyre shown.
All wheels yellow
A flat tyre or major loss of tyre inflation pres‐
sure in several tyres.
Wheels grey
The system cannot detect a flat tyre. The rea‐
sons for this are:▷System reset is performed.▷Malfunction.
Additional information
The current tyre inflation pressures and, de‐
pending on the model, tyre temperatures are
also displayed in the status control display.
The values shown are current values and may
change due to the effect of driving mode or
weather conditions.
Running reset Reset the system after adjusting the tyre pres‐
sure to a new value and after a tyre or wheel
change.
On the Control Display and on the vehicle:
1."Vehicle information"2."Vehicle status"3. "Perform reset"4.Start the engine – do not drive off.5.Resetting tyre pressure: "Perform reset".6.Drive off.
The wheels are shown grey and the status ap‐
pears on the display.
After driving for a short time over 30 km/h,
19 mph the set tyre inflation pressures are ac‐
Seite 107SecurityControls107
Online Edition for Part no. 01 40 2 964 013 - VI/15
Runflat indicator RPA
Principle The system identifies a loss of tyre pressure
by comparing the speeds of rotation of the in‐
dividual wheels while the vehicle is in motion.
If a tyre loses pressure, its diameter changes.
This in turn alters the rotational speed of the
corresponding wheel. This is detected and re‐
ported as a flat tyre.
The system does not measure the tyre pres‐
sures as such.
Operating requirements
The system must have been initialised with
correct tyre inflation pressure, otherwise relia‐
ble signalling of a flat tyre cannot be assured.
Each time the tyre pressure is adjusted or a
tyre or wheel is changed, initialise the system
again.
Status display The current status of the runflat indicator can
be shown on the Control Display, for example
whether the runflat indicator is active.
On the Control Display:1."Vehicle information"2."Vehicle status"3. "Flat Tyre Monitor (RPA)"
The status is displayed.
Initialising
On initialisation, the current tyre pressures are
stored as a reference for detection of a flat tyre. The initialisation is started by confirming
the correct tyre inflation pressures.
When driving with snow chains fitted, do not
initialise the system.
On the Control Display:
1."Vehicle information"2."Vehicle status"3. "Perform reset"4.Start the engine – do not drive off.5.Start the initialisation with "Perform reset".6.Drive off.
Initialising is completed while the vehicle is in
motion; this process can be interrupted at any
time.
Initialising resumes automatically when you
continue your journey.
Message of a flat tyre The yellow warning lamp is illuminated.
A Check Control message is shown.
There is a flat tyre or substantial loss of
tyre pressure.
1.Reduce your speed and carefully stop the
vehicle. Avoid violent or sudden braking
and steering manoeuvres.2.Determine which wheel is damaged. Do
this by checking the tyre inflation pres‐
sures with the aid of the Mobility System. If
all tyres are inflated to the correct pres‐
sures, the runflat indicator might not have
been initialised. In this case initialise the
system.3.Remedy the flat tyre with the Mobility Sys‐
tem or replace the damaged wheel.
System limits
A natural, even loss of tyre pressurein all four
tyres that occurs over time is not detected.
Consequently, check the tyre inflation pres‐
sure at regular intervals.
No warning can be given in the event of sud‐
den tyre failure caused by external factors.
In the following situations, the system could be
slow to respond or operate incorrectly:
▷If the system has not been initialised.▷Journey on snow-covered or slippery sur‐
faces.Seite 109SecurityControls109
Online Edition for Part no. 01 40 2 964 013 - VI/15
