2003 Mercedes-Benz SL-Class Electrical System Problems

I am concerned with the battery control module. I have noticed there has been a lot of incidents out there where the battery control module in the SL 500s have caught fire! I am concerned for my safety due to this defect!

To who may this concerned, I have a 2003 Mercedes SL500 and recently found my battery control module caught on fire and burnt a section of my car. I have tried reaching out to Mercedes directly first and they said the car is 20 years ago and it could have not be a manufactured defect. Please I need help this problem could’ve burn down my house or while I was driving. Mercedes requested I send them a letter in writing if I have to get the car inspected. Please setup and date so I can write them this is 100% liability on their brand as there is no schedule maintenance for a battery control module.

It appears the BCM (Battery Control Module) caught fire and burned a significant portion of the trunk and associated wiring.

The battery control module (known as the BCM or BNS) failed, triggering a fire. The incident occurred while the vehicle was parked in a garage and had not been operated for several weeks. The fire consumed the module, insulation on wiring connected to and close to the module, part of the trunk lining material, and burned through a total of five hydraulic lines (retractable roof hydraulics). It appears that the trunk seal limited air to the point that the fire was self extinguished. This is the only thing that saved the attached garage and house. The vehicle valued at $30,000 was determined to be a total loss due to the extensive repairs required to restore it to an operating condition. I have since joined a Facebook group "Mercedes BNS/BCM Fires" that has nearly 1000 members and found that this is a common issue with the Mercedes R230 model and fires have occurred dozens if not hundreds of times. We have determined that the module has undergone numerous changes, but there is no confirmation that any are safe. Mercedes refuses to provide guidance or solutions to this issue and apparently has no regard for the safety of current owners. I have retained the failed module, wiring, hydraulic lines, and burned portion of the trunk lining. It is available for inspection or analysis. I am a mechanical engineer with over 35 years experience in the automotive and industrial areas.

SOMETIMES WHEN I START THE CAR THE LIGHTS ON THE DASH WILL NOT COME ON AND NONE OF THE GAUGES WORK ! THEN I TURN IT OFF AND BACK ON AGAIN AND IT WORKS! ALSO WHEN I'M DRIVING AND HIT A LITTLE BUMP ON THE FREEWAY AND ROAD THE DASH LIGHTS TURN RED AND SAYS DRIVE CAREFULLY THEN 2 SECONDS LATER GOES BACK TO NORMAL!

TL* THE CONTACT OWNS A 2003 MERCEDES BENZ SL500. THE CONTACT STATED THAT WHILE TURNING ON THE VEHICLE, THE INSTRUMENT PANEL AND OTHER UNKNOWN ELECTRICAL FUNCTIONS FAILED TO OPERATE. THE VEHICLE WAS NOT DIAGNOSED OR REPAIRED. THE MANUFACTURER WAS NOT MADE AWARE OF THE FAILURE. THE FAILURE MILEAGE WAS 110,000.

IGNITION SHUT OFF MULTIPLE TIMES OVER DAYS WHILE DRIVING CUTTING OFF ALL ELECTRICAL RADIO, BRAKES STEERING ETC HAS HAD ELECTRICAL PROBLEMS SINCE 2004 OR 2005 WITH BATTERY SUDDENLY BEING DEAD BOTH ACCESSORY BATTERY IN TRUNK AND STARTING BATTERY AND HAS HAD MANY THOUSANDS OF DOLLARS SPENT ON VARIOUS PARTS AND COMPUTERS THAT WERE SAID TO BE DRAWING DOWN THE BATTERY, ABOUT A YEAR AGO CONTACTED PRESIDENT OF MB NORTH AMERICA AND GOT NO HELP FROM CUSTOMER REP THEN LAST MONTH CAR LEFT ME IN INTERSECTION ONE TIME AND IN EXPRESSWAY ENTRANCE LANE ANOTHER TOTALLY SHUT DOWN ALL ELECTRICAL POWER BRAKES STEERING RADIO LIGHTS ETC AND LUCKILY WASN'T KILLED ALTHOUGH DRIVERS SKIDDED AND BLEW HORN ETC. CAR THEN WOULD THEN CRANK AND FLASH RED EMERGENCY TAKE TO SHOP MESSAGE GOT IT CRANKED AND LIMPED HOME PICKED UP BY DEALER WHO COULD NOT GET IT TO CRANK OR TURN ON ANYTHING ELECTRICAL DEAD AND THEY TOWED OFF BLAMED PROBLEM IN IGNITION KEY ASSEMBLY AND I CALLED PRESIDENT OF MB AGAIN NO HELP BILL OVER 2K HAVE LEARNED FROM COMMUNITY MB SHOP "EVERYBODY KNOWS THAT THE 03 AND 04 SL 500 HAD THIS ELECTRICAL PROBLEM BUT MB HAS NEVER ACKNOWLEDGED IT. I AM SURE I WOULD HAVE HAD ACCIDENT IF OTHER DRIVERS HAD NOT BEEN ALERT. THERE MUST BE SIMILAR ISSUES WITH THIS ELECTRICAL DEFECT IF THE MECHANIC IN THE COMMUNITY KNOWS OF IT. SOUNDS JUST LIKE THE GM IGNITION PROBLEM ONLY FEWERESL500S THAN GM CARS I WOULD THINK. *TR

WHILE DRIVING TO WORK, I WAS GOING ABOUT 35 MPH WHEN THE DASH LIGHTS UP RED SAYING "SERVICE BRAKES, STOP VEHICLE, ETC". MY MECHANIC LOOKED OVER EVERYTHING TO DO WITH BRAKES AND COULD NOT FIX IT. HE CALLED MERCEDES OF TALLAHASSEE AND WAS TOLD IT WAS AN ELECTRICAL ISSUE THAT WAS A COMMON PROBLEM WITH THIS VEHICLE. IT DID HAVE A RECALL ON IT, BUT IT EXPIRED IN JULY LAST YEAR, JUST MY LUCK. SO I GOOGLED IT AND HAVE NOW FOUND TONS OF PEOPLE WITH THE SAME EXPERIENCE! HOW CAN THE VEHICLE SAFETY ADMINISTRATION LEGALLY ALLOW MERCEDES BENZ TO CONTINUE LETTING THIS HAPPEN TO PEOPLE? HOW MANY ACCIDENTS MUST TAKE PLACE, OR GOD FORBID DEATHS BEFORE SOMETHING IS DONE? I HAVE NO OPTION BUT TO PAY OUT OF POCKET TO HAVE THIS PIECE OF $100K JUNK FIXED AND PRAY IT NEVER HAPPENS AGAIN! MERCEDES BENZ AND THE VEHICLE SAFETY ADMINISTRATION BETTER PRAY THIS DOESN'T CAUSE AN ACCIDENT OR I WILL SUE THE [XXX] OUT OF BOTH! INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6). *TR

IGNITION FAILURE, NO KEYS WORK TO START THE VEHICLE (IT DOESN'T RECOGNIZE THE KEYS) CAR HAD TO BE PUT ON A FLATBED TRUCK AND SENT TO DEALER FOR REPAID. *TR

I TURNED KEY AND CAR DID NOT START. I ENDED UP GETTING STUCK EITHER AT HOME OR IN A SHOPPING CENTER. CAR HAD TO BE PUT ON A FLAT BED. DEALER RELPACED PARTS EACH TIME , BUT COULD NOT FIND THE CAUSE OF THE PROBLEM.