126 Automatic transmission
8_ WARNING
-Unintended vehicle movement can cause
serious injury .
- Never leave your vehicle with the engine
running while in gear. If you must leave
your vehicle when the engine is running,
activate the parking brake and move the
selector lever to P.
- Power is still transmitted to the wheels
when the engine is running at idle. To
prevent the vehicle from "creeping", you
must keep your foot on the brake when
the engine is running and the selector lever is in D/S or R or "tiptronic" mode is
selected.
- Do not press the accelerator pedal when
changing the selector lever position
while the vehicle is stationary and the
engine is running.
- Never shift into
R or P while driving.
- Before driving down a steep slope, re-
duce your speed and shift into a lower
gear with "tiptronic".
- Do not ride the brakes or press the brake
pedal too often or too long when driving
down a hill. Constant braking causes the
brakes to overheat and substantially re
duces braking performance, increases
braking distance or causes complete fail
ure of the brake system .
- To preven t the vehicle from rolling back
when stopping on inclines, always hold it
in place with the brake pedal or parking
brake.
- Never hold the vehicle on an incline with
a slipping clutch . The clutch opens auto
matically when it becomes too hot from
the overload. An indicator lamp
[O] illu
minates and a driver message appears
<=:> page 128when the clutch is overload
ed.
- If the engine must remain running, never
have any driving position engaged when
checking under the hood. Make sure the
selector lever has securely engaged and
is locked in P with the parking brake set
r:::> page 231 . Otherwise, any increase in engine speed may set the vehicle in mo
tion, even with the parking brake ap
plied.
(D Note
- When stopping on an incline , do not try
to hold the vehicle in place by pressing
the accelerator pedal while a driving gear is selected. This can cause the transmis
sion to overheat and can damage it. Acti
vate the parking brake or press the brake pedal to prevent the vehicle from rolling .
- Allowing the vehicle to roll when the en
gine is stopped and the selector lever is
in N will damage the transmission be
cause it is not lubricated under those cir
cumstances.
@ Tips
For safety reasons, the parking brake is re
leased automatically only when the driv
er's safety belt is engaged in the buckle.
Hill descent control
The hill descent control system assists the
driver when driving down declines.
Hill descent control is activated when these
lector lever is in D /S and you press the brake
pedal. The transmission automatically selects
a gear that is suitable for the incline. Hill de
scent control tries to maintain the speed ach
ieved at the time of braking, within physical
and technical limitations. It may still be nec
essary to adjust the speed with the brakes .
Hill descent control switches off once the de
cline levels out or you press the accelerator
pedal.
When the speed is set in the cruise control
system
r:::> page 95, hill descent control is also
activated.
A WARNING
-
Hill descent control cannot overcome
physical limitations, so it may not be able
to maintain a constant speed under all
24 0 Ch eck ing and filling
pressure relief valve in the cap when the en
gine becomes hot.
A WARNING
- The coo ling system is under pressure and
can get very hot. Reduce the risk of
sca lding from hot coolant by following
these steps.
- Turn off the eng ine and a llow it to cool
down.
- Protect your face, hands and arms from escap ing fl uid and steam by cover ing
the cap with a large, thick rag.
- T urn the cap slowly and very carefully
in a counter-clockwise direction while
applying light, downward pressure on
the top of the cap.
- To avo id being burned, do not sp ill an
tifreeze or coolant on the exhaust sys
tem or hot engine parts. Under certain
conditions, the ethylene glyco l in en
g ine coolant can catch fire.
- Antifreeze is poisonous. Always store an
t ifreeze in its or iginal container and well
out of the reach of children.
- If you drain the coolant, it must be caught and safely stored in a proper con
tainer clear ly marked "poison".
- Coolant pollutes the environment and
could cause an engine fire. Excess coo l
ant will be forced out through the pres
sure re lief valve in the cap when the en
gine becomes hot.
- If, in an emergency, only water can be
added, the correct ratio between water
and antifreeze~
page 238 must be re
stored as soon as possib le.
@ For the sake of the environment
Dra ined coolant should not be reused. Al
ways dispose of used coolant while observ
ing all environmental regulations.
Radiator fan
The radiator fan switches on automatically by
itself.
The radiator fan is driven by the engine via the
V-belt. The viscous clutch regulates the speed
of the fan according to the temperature of the
coolant .
An auxiliary electric radiator fan* sw itches on
and off depending on coolant temperature
and other vehicle operat ing condit ions.
After you switch the engine off, the aux iliary
fan can continue running for up to 10 m inutes
- even w ith the ignition off. It can even switc h
on again later by itself
c> &. , if
- the temperature of the engine coo lant r ises
due to the heat build-up from the engine in
the engine compartment, or
- the engine compartment heats up because the vehicle is parked in intense sunlight.
A WARNING
- To reduce the risk of personal injury nev
er touch the radiator fan .
- The auxiliary electric fan is temperature
controlled and can sw itch on suddenly
even when the engine is not running.
- The auxiliary radiator fan sw itches on au
tomatically when the engine coo lant
reaches a certain temperature and w ill
con tinue to run until the coolant tempe r
a ture drops.