The Mercedes Benz S430 is part of the S-Class family of cars from manufacturing giant Mercedes Benz. Initially, the car had a 5-speed 5G-Tronic transmission, but in 2003, it was offered with the newer 7-speed 7G-Tronic transmission. It was part of a series of flagship sedans called W220. The W220 sedans were started in 1992, designed and approved in 1994, and debuted in 1999. The car has been plagued with a few common problems that prompted some recalls.
In an S430, the chances of the airmatic suspension pump relay failing is high. A slipping relay means the pump might run continuously. This can result in either one of two things: the pump motor can fail because of overuse, or the battery can die before the motor does. This is because the pump motor will continue to run after the car is turned off. Worn airmatic pump mount bushings can also cause noises in the front axle while driving on an uneven road. Additionally, the pump might produce buzzing noises while it is running.
The S430 has been observed to leak fluid from the electrical connector at the automatic transmission. Leaking fluid could infect the wiring harness and damage the transmission control module. When that happens, the harness and control module might need replacing.
The trunk lid springs on the S430 may fail and may cause the trunk lid to remain in an open position. Almost 17,000 vehicles were recalled by Mercedes in 2004. Dealers replaced both trunk lid springs, as keeping them when they are damaged poses a great risk of injury.
Corrosion may occur in the inner steel portions of the Active Body Control's high-pressure distribution hose of the S430. The deterioration of the hose is caused by extensive exposure to humidity. This, in turn, can result in hydraulic fluid leak near the catalytic converter. The leaking fluid may contaminate hot engine components and possibly start a fire. Mercedes Benz recalled a significant number of vehicles with this problem in 2007, and dealers replaced the worn hose with a corrosion-resistant ABC high-pressure distribution hose.