Engine misfires (rough running) and lack of power are commonly caused by ignition coil pack or ignition module faults. Proper diagnoses should isolate the cause and prevent unnecessary replacement of good parts.
Resources for the Repair and Maintenance of your 2009 Mercedes-Benz SL600
2009 Mercedes-Benz SL600
2009 Mercedes-Benz SL600 Problems
The electrical connector at the automatic transmission may leak fluid. Over time leaking fluid could migrate through the wiring harness and damage the transmission control module. If that happens a new harness and control module may be necessary to correct the problem.
This vehicle has sensotronic brake control (SBC). If the SBC light on the dash illuminates, have the brakes checked. If the SBC is not working, limited brake pressure is delivered to the front brakes, increasing the distance it takes to stop. The SBC hydraulic unit has a specific service life programmed into the control module. Follow the manufacturer's recommended service procedure for proper maintenance of the SBC.
The active body control system can leak fluid from numerous areas, including the tandem pump, hydraulic lines, struts, and/or seals. If it is not repaired, the vehicle ride height could drop too low and cause damage to the undercarriage.
On higher mileage vehicles, wear causes noise at the vario roof seals. Lubricating the seals can usually cure the problem; in most cases, the seals do not need replacement.