Mercedes-Benz S-Class 2007 - Manual (Page 512)

511
Operation
Tires and wheels
Checking tire inflation pressure
Regularly check your tire inflation pressure
at least once a month.
Check and adjust the tire inflation
pressure when the tires are cold. The tires
can be considered cold if the vehicle has
been parked for at least 3 hours or driven
less than 1 mile (1.6 km).
If you check the tire inflation pressure
when the tires are warm (the vehicle has
been driven for several miles or sitting less
than 3 hours), the reading will be
approximately 4 psi (0.3 bar) higher than
the cold reading. This is normal. Do not let
air out to match the specified cold tire in-
flation pressure. Otherwise, the tire will be
underinflated.
Checking tire inflation pressure
manually
Follow the steps below to achieve correct
tire inflation pressure:
̈ Remove the cap from the valve on one
tire.
̈ Firmly press a tire gauge onto the
valve.
̈ Read tire inflation pressure on tire
gauge and check against the recom-
mended tire inflation pressure on the
placard on the driver’s door B-pillar
(
୴ page 503). If necessary, add air to
achieve the recommended tire inflation
pressure.
̈ Install the valve cap.
̈ Repeat this procedure for each tire.
Checking tire inflation pressure elec-
tronically with the Advanced Tire Pres-
sure Monitoring System (Advanced
TPMS)*, (standard on U.S. vehicles)
i If you have overfilled the tire, release tire in-
flation pressure by pushing the metal stem of the
valve with e.g. a tip of a pen. Then recheck the
tire inflation pressure with the tire gauge.
i The Advanced T ire P ressure M onitoring
S ystem (Advanced TPMS) is equipped with a
combination low tire pressure/TPMS malfunc-
tion telltale in the instrument cluster
(
୴ page 28). Depending on how the telltale illu-
minates, it indicates a low tire inflation pressure
condition or a malfunction in the TPMS system it-
self:
ț If the telltale illuminates continuously, one
or more of your tires is significantly under-in-
flated. There is no malfunction in the TPMS.
ț If the telltale flashes for 60 seconds and
then stays illuminated, the TPMS system it-
self is not operating properly.