There are 5 owner-reported electrical system complaints for the 2005 Mercedes-Benz SL-Classin NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
The BCM in the SL class (Mercedes chassis code r230) fails very often. It catches fire and burns down vehicles in MANY instances. Mercedes is not selling a replacement part because they want to save money. THIS VEHICLE HAS AN ELECTRONIC ASSISTED BRAKING SYSTEM!!! The BCM balances battery loads in the vehicle. When it fails it can make any electronic system in the car malfunction or simply not work. This could be as simple as the car not starting or as severe as it burning down your ENTIRE HOME. I would be okay if they simply sold a replacement part but they DO NOT forcing all owners of this vehicle to drive it despite the condition of that battery module. All I’m asking is for a part to be made. No one has managed to make a replacement or refurbished part but Mercedes who turned their backs on us. They were refurbishing the parts but stopped for some unknown reason. This is dangerous for all owners of the Mercedes SL chassis code r230. Please help you’re the only ones that can.
TL* THE CONTACT OWNS 2005 MERCEDES BENZ SL500. THE CONTACT STATED THAT THE WHOLE RIGHT SIDE OF THE VEHICLE TRUNK CAUGHT ON FIRE WHILE THE VEHICLE WAS PARKED. THE CONTACT STATED THAT THE FIRE STARTED IN THE UPPER RIGHT FRONT AREA OF THE TRUNK WHERE THEY WERE WIRES AND SAW SPARKS. THE CONTACT STATED THAT THE FIRE WENT OUT ON ITS OWN BECAUSE THERE WAS NO OXYGEN. THE VEHICLE WAS NOT TAKEN TO A DEALER OR AN INDEPENDENT MECHANIC FOR DIAGNOSTIC TESTING. THE MANUFACTURER WAS MADE AWARE OF THE FAILURE AND INFORMED THE CONTACT THAT THEY WILL TOW THE VEHICLE TO MERCEDES-BENZ OF OAKLAND (2915 BROADWAY, OAKLAND, CA 94611). THE APPROXIMATE FAILURE MILEAGE WAS 90,000.
MY MERCEDES BENZ HAS A FAULTY ELECTRICAL WIRING IN THE COMMAND NAVIGATION UNIT IN MY SL500. THE VEHICLE HAS ONLY 16,385 MILES ON IT, THOUGH IT IS A 2005 MODEL, AND HAS BEEN HOUSED IN A HIGH-END GARAGE WITH NO TRAUMA, NO DAMAGE, AND VERY LITTLE WEAR AND TEAR. I PURCHASED THE CAR USED ABOUT 6 WEEKS AGO. WITHIN THE LAST 3 WEEKS THE UNIT HAS GONE FROM WORKING INTERMITTENTLY TO NOT WORKING AT ALL, SIMPLY PROVIDING A SCREEN MESSAGE: SYSTEM UNAVAILABLE. ON MARCH 5, 2012 I TOOK MY SL 500 THE AUTHORIZED DEALER HERE, AND CONTACTED THE SERVICE MANAGER . AFTER HAVING MY VEHICLE OUT OF COMMISSION FOR TWO DAYS, I READ THE DIAGNOSIS/REPAIR REPORT AND WAS TOLD THIS WAS NOT AN ERROR BY ME OR THE PREVIOUS OWNER BUT SOMETHING THAT HAPPENED SOMEWHERE IN THE MANUFACTURING PROCESS, PROBABLY ON THE ASSEMBLY LINE, AS THE SOUND AMPLIFIER HAD AN INTERNAL ELECTRICAL FAULT. ADDITIONALLY, I HAVE BEEN TO TWO INDEPENDENT MERCEDES BENZ DEALERS AND THEY COULD NOT FIX THE PROBLEM. I'VE ALSO LEARNED THAT I CANNOT SIMPLY REPLACE THE STEREO WITH A WORKING MODEL FROM ANY ELECTRICAL STORE (LIKE BEST BUY OR CAR STEREO GUYS). IT IS MY UNDERSTANDING THAT TO REPLACE THE COMMAND UNIT WOULD COST SEVERAL THOUSAND DOLLARS. IT IS MY BELIEF THAT WHILE THE CAR IS NOT WITHIN A TYPICAL FIVE OR SIX YEAR WARRANTY PERIOD (I JUST MISSED THAT PERIOD) IT IS CLEARLY A CAR THAT HAS BEEN WELL TAKEN CARE OF, BARELY DRIVEN, PROPERLY HOUSED, AND MAINTAINED. GIVEN THE FINDINGS FROM YOUR AUTHORIZED TECHNICIANS, IT SEEMS THAT THIS IS A PROBLEM THAT CAME WITH THE CAR THAT WOULD HAVE SURFACED AT SOME POINT. LUCKY ME THAT IT IS SURFACING NOW. I AM HOPING THAT THE NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION WILL CONTACT MERCEDES ABOUT THIS FAULTY COMMAND UNIT. THERE ARE MANY OTHER MERCEDES OWNERS WHO HAVE AND ARE EXPERIENCING THIS ELECTRICAL NIGHTMARE. *TR
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
INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6). SOMETIME AGO I WROTE YOU ABOUT COMPUTER PROBLEMS IN MY MERCEDES BENZ. YOU RESPONDED THAT YOU WILL INVESTIGATE IT AND SHARE THE RESULT WITH ME. HAVE NOT HEARD FROM YOU SINCE. ANYTHING NEW? *TR THE CONSUMER STATED HE WAS EXPERIENCING COMPUTER PROBLEMS. THE CONSUMER WANTED TO KNOW THE STATUS OF HIS COMPLAINT. THE CONSUMER CHECKED THE INJURY BOX AND CRASH BOX, BUT DID NOT INDICATE ANY TYPE OF ACCIDENT IN THE COMPLAINT. UPDATED IVOQ 04/28/10.*JB UPDATED 09/01/10
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
Data synced from NHTSA on Apr 25, 2026