Possible reasons for changes in the way the rain sensor works
The rain sensor may misread what is happening in the detection zone of its sensitive rain-sensor
surface ⇒ fig. 91 (arrow) and not work for a number of reasons; which include:
x Worn out wiper blades: Worn out wiper blades may leave a film of water or wiping streaks; this can
cause the wipers to run longer, to wipe more often, or to wipe continuously at high speed.
x Insects: Insects hitting the sensor may trigger the wipers.
x Salt streaks: Salt streaks on the windshield from winter driving can cause wiping more often or
continuously on glass that is almost dry.
x Dirt: Caked-on dust, wax, any other build-up on the windshield (lotus effect), or car-wash detergent
residue can lower the rain sensor's sensitivity and cause it to react too slowly or not at all.
x Crack or chip in the windshield: If a stone hits and chips the windshield while the rain sensor is on,
this will trigger a wiper cycle. After that, the rain sensor will recognize the change and recalibrate itself
to respond to the sensitive surface's reduced detection zone. Depending on the size of the chip, the
sensor's reaction pattern may or may not change.
WARNING
The rain sensor cannot always recognize rain and activate the wipers.
x Switch the wipers on manually when water on the windshield reduces visibility.
Clean the rain sensor's sensitive surface (arrow) regularly and check the wiper blades for wear or
damage.
To remove wax and coats of polish safely, we recommend using an alcohol-based windshield
cleaner.
Checking and refilling windshield washer fluid
Fig. 92 In the engine compartment: Cap of the windshield washer fluid reservoir.
To help make it more difficult to steal your vehicle, you should always make sure the steering column
is locked before leaving the vehicle.
Electronic steering column lock
Vehicles with Keyless Access: The steering column is locked if the driver door is opened with the
ignition switched off. The vehicle must be standing still and the transmission must be in Park (P) on an
automatic transmission vehicle.
If the driver door is opened before the ignition is switched off, the electronic steering column lock is
activated only after the vehicle has been locked with the vehicle key or via the sensor in the door
handle.
Mechanical steering column lock
Vehicles without Keyless Access: The steering column is locked if the vehicle is stationary and the
vehicle key is removed from the ignition switch.
Engaging the steering column
lock
Disengaging the steering column
lock
Parking the vehicle Turn the steering wheel slightly to
take pressure off the steering
column lock.
Remove the vehicle key. Insert the vehicle key into the
ignition switch.
Turn the steering wheel slightly until
you hear the steering column lock
engage.
Hold the steering wheel in this
position and turn the ignition switch.
Power steering
Power steering automatically adjusts to driving speed, steering torque, and the steering angle of the
wheels. Power steering works only when the engine is running.
If power steering is reduced or lost completely, it will be much harder to steer and control the vehicle.
Counter-steering assistance
Counter-steering assistance is part of Electronic Stability Control (ESC). This feature makes it easier
for the driver to control the vehicle in difficult situations. For example, if you have to brake hard on a
surface that provides uneven traction, the vehicle could pull to the right or left. ESC detects this
situation and helps the driver counter-steer with additional steering power ⇒ .
WARNING
The counter-steering assistance in ESC can do no more than help the driver steer in difficult
situations. The driver must still control the vehicle. The vehicle does not steer by itself with
this feature!
NOTICE
If the ignition is off, the steering column lock will engage and the vehicle cannot be steered.
For this reason, you must leave the ignition on when going through an automatic car wash, for
example, so that the wheels will still steer.