center console MERCEDES-BENZ C-CLASS 1999 User Guide

Acceleration Slip Regulation (ASR)
The acceleration slip regulation will engage at all vehicle s peeds, if one or both drive wheels begin to lose traction
and spin in acceleration. While engaged, the yellow warni ng lamp in the speedometer dial flashes. With the
acceleration slip regulation engaged, the brake is applied to the spinning drive wheel until slip is brought under
control. If both drive wheels spin, the brake is applied to both drive wheels and simultaneously, engine torque is
limited, to improve the vehicle's driving stability. As traction on the road surface increases, thus allowing
acceleration without slip, the allowable engine torque also increases again and the brake is no longer applied to
drive wheels.

Important !
If the ASR warning lamp flashes, adapt your spee d and driving to the prevailing road conditions.

Caution !
If the vehicle is towed with the front axle raised (see Towing the vehicle in Index), t he engine must be shut off
(electronic key in steer ing lock position 0 or 1). Othe rwise, the acceleration slip regulation will immediately be
engaged and will apply the rear wheel brakes.

Notes:
The indicator lamp for the ASR is combined with that of the BAS The yellow BAS/ASR malfunction indicator
lamp in the instrument cluster and the yellow ASR warning lamp in the speedometer dial come on with the
electronic key in steering lock position 2. They should go out with the engine running. If the BAS/ASR malfunction
indicator lamp comes on with the engine running, a malfunc tion has been detected in either system. Pressing the
accelerator pedal will require greater effort. Only partial engine output will be available.
If the BAS malfunctions, the brake system functions in the usual manner, but without BAS. Have the BAS or ASR
checked at your authorized Mercedes-Benz dealer as soon as possible. With the ABS malfunctioning, the ASR
is also switched off. Driving the vehicle with varied size tires will cause the wheels to ro tate at different speeds,
therefore the acceleration slip regulation may activate (ye llow ASR warning lamp in speedometer dial comes on).
For this reason, all wheels, including the spare wheel, mu st have the same tire size. When testing the parking
brake on a brake test dynamometer, the engine must be shut off. Otherwise, t he acceleration slip regulation will
immediately be engaged and will apply the rear wheel brakes . In winter operation, the maximum effectiveness of
the acceleration slip regulation is only achieved with Mercedes-Benz recommended M+S rated radialply tires
and/or snow chains.

ASR Control Switch



ASR control switch located in center console To improve
the vehicle's traction when driving with snow chains, or
starting off in deep snow, sand or gravel, press the upper half of the ASR switch. The ASR warning lamp, located
in the speedometer dial, is cont inuously illuminated. With the ASR system switched off, the engine torque
reduction feature is cancelled. Therefore, the enhanced vehicle stability offered by ASR is unavailable. Adapt your
speed and driving to the prevailing road conditions. A por tion of the ASR system remains active, even with the
switch in the OFF position. If one drive wheel loses traction a nd begins to spin, the brake is applied until the wheel
regains sufficient traction. The traction control engages at vehicle speeds up to approximately 24 rnph (40 km/h),
and switches off at 50 mph (80 km/h).
Note:
Avoid spinning of one drive wheel. Doing so may cause seriou s damage to the drive train which is not covered by the
Mercedes-Benz Limited Warranty.
The ASR warning lamp, located in the speedometer dial, star ts to flash at any vehicle speed as soon as the tires
lose traction and the wheels begin to spin. To return to the enhanced vehicle stability offered by ASR: press lower
half of the switch (the ASR warning lamp in the speedometer dial goes out).

Important!
If the ASR warning lamp flashes:
• during take-off, apply as little throttle as possible,
• while driving, ease up on the accelerator.


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