2010 Mercedes GL-Class Owner's Manual - Page 317

What to do if ... Brake Problem ! The yellow ABS indicator lamp comes on while the engine is running. Possible causes/consequences and M Solutions The ABS has detected a malfunction and switched off. The BAS, the ESP® and the PRE-SAFE® are also switched off. The brake system is still functioning normally but without the systems specified above available. If the ABS control unit is malfunctioning, other systems such as the navigation system or the automatic transmission may also be malfunctioning. X Continue driving with added caution. Wheels may lock during hard braking, reducing steering capability. X Read and observe messages that may appear in the multifunction display (Y page 287). X Have the system checked at an authorized Mercedes-Benz Center as soon as possible. Failure to follow these instructions increases the risk of an accident. The ABS has switched off due to insufficient power supply. The battery might not be charged sufficiently. When the voltage is above the required value again, the ABS is operational again. The ABS indicator lamp should go out. X If the ABS indicator lamp does not go out: Have the alternator and the battery checked. The self-diagnosis has not been completed yet. The indicator lamp will go out after driving a short distance at a vehicle speed of above 12 mph (20 km/h). 315 ! The yellow ABS indicator lamp comes on while the engine is running. ! The yellow ABS indicator lamp comes on while the engine is running. Z Practical hints