2006 Mercedes CLS-Class Owner's Manual - Page 92

Safety and Security Driving safety systems i If the electro-hydraulic brake system is activated as the brake pedal is first depressed, you may feel a reduced pedal resistance and longer pedal travel than normal. When releasing the pedal, you may also feel the brake pedal pulsate and you may hear a sound which is caused by the activation of the electro-hydraulic brake system pump. This is normal and not an indication of a malfunction. Pedal travel returns to normal when you release the brake pedal and the sound soon ceases. If you experience the above while driving and the red brake warning lamp ( page 354) illuminates and/or warning messages appear in the instrument cluster ( page 363), the brake system is malfunctioning. Follow the instructions of the warning message(s) and have the brake system checked immediately. Warning! G The electro-hydraulic brake servo assistance switches off automatically approximately 2 minutes after you turned the SmartKey in the starter switch to position 0 or removed the SmartKey approximately 2 minutes after you pressed the KEYLESS-GO* start/stop button to turn off the engine or power supply and opened the driver's door (with driver's door open, the starter switch is set to position 0, same as SmartKey removed from starter switch) approximately 20 seconds after you locked the vehicle from outside Have brake pad replacement and other work on the electro-hydraulic brake system carried out by qualified technicians only. Contact an authorized Mercedes-Benz Center for further information. The electro-hydraulic brake system must be deactivated prior to working on the system. High pressure is intermittently built up in the system as part of its automatic self-test. In addition, the system is automatically activated when the vehicle is unlocked by SmartKey, when the driver or passenger door is opened, when the starter switch is turned to position 1, when the brake pedal is depressed or when the parking brake is released. Failure to deactivate the system prior to maintenance will cause brake pistons to extend and brake fluid to leak, which may result in injuries (contusions and acid burns). Extended brake pistons may also cause injury. 91