2010 Mercedes GLK-Class Owner's Manual - Page 291

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 EBP 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 Adjust driving to be consistent with reduced braking responsiveness. X Read and observe messages that may appear in the multifunction display (Y page 262). 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 Continue driving with added caution. Wheels may lock during hard braking, reducing steering capability. X Adjust driving to be consistent with reduced braking responsiveness. X Read and observe messages that may appear in the multifunction display (Y page 262). X If the ABS indicator lamp does not go out: Have the alternator and the battery checked. 289 ! The yellow ABS indicator lamp comes on while the engine is running. Z Practical hints