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.
2003 Mercedes Benz SL55
Owners filed 11 complaints about this vehicle with federal regulators, most often about the service brakes, hydraulic. No safety recall has been issued.
| Component | Reports | Crashes | Fires | Injuries | |
|---|---|---|---|---|---|
| Service Brakes, Hydraulic | 2 | 1 | 0 | 1 | |
| Fuel System, Gasoline | 2 | 0 | 0 | 0 | |
| Electrical System | 2 | 0 | 2 | 0 | |
| Unknown or Other | 1 | 0 | 0 | 0 | |
| Suspension | 1 | 0 | 0 | 0 | |
| Power Train | 1 | 0 | 0 | 0 | |
| Fuel/Propulsion System | 1 | 0 | 0 | 0 | |
| Engine and Engine Cooling | 1 | 0 | 0 | 0 |
What owners reported
Newest filingsIt appears the BCM (Battery Control Module) caught fire and burned a significant portion of the trunk and associated wiring.
My car (the SL55 and all SL models) has a "Battery Control Module" (BCM) also referred to as the "Battery Stabilization Control Load Module" which shows signs of imminent failure which will lead to a meltdown or fire. I inspected the module after finding that this was a common problem with these cars online. This model of car has been documented to completely catch on fire, even when parked after driving. I have pictures of the burnt board inside my BCM. I am very concerned as it could literally burn my house down. The typical warning for this issue is a red colored warning on the dash LCD display, however I didn't have that warning as my unit is apparently still functioning even though it's compromised.
PLASTIC PIECE ON GEARSHIFT ASSEMBLY BROKE NOT ALLOWING CAR TO BE PLACED IN GEAR. IS APPARENTLY A PROBLEM WITH 1000'S OF THESE CARS BASED ON INTERNET SEARCH. CONTACTED MERCEDES AND THEY SAID NOT THEIR PROBLEM. THEY CHARGE $1300.00 TO FIX THE PROBLEM. THEY STATED TO SAVE MONEY ON THIS PART BEING REPLACED TO TAKE A MALLET AND FINISH BREAKING PIECE THEREBY RENDERING CHILD SAFETY FEATURE USELESS. APPARENTLY LOOKING AT THE INTERNET THIS IS WHAT 1000'S OF PEOPLE HAVE ALREADY DONE. HOW MERCEDES THINKS THIS IS A NOT A SAFETY CONCERN IS BEYOND ME. IT IS AN EXTREMELY DANGEROUS SITUATION TO ALL CHILDREN AS THEY WILL BE ABLE TO PUT CAR INTO GEAR WITH NO SAFETY PRECAUTIONS. I CAN SEE MANY CHILDREN EVENTUALLY PUTTING THESE CARS IN GEAR AND GETTING HURT.
INTERNAL GAS TANK BAFFLE HAS COME LOOSE INSIDE THE GAS TANK. THIS CAUSES A CONSISTENT AND VERY ANNOYING RATTLING SOUND. *TR
TL* THE CONTACT OWNS A 2003 MERCEDES BENZ SL55 AMG. THE CONTACT STATED THAT WHILE DRIVING AT VARIOUS SPEEDS, HE COULD HEAR SOMETHING MOVING ABNORMALLY WITHIN THE FUEL TANK. THE VEHICLE WAS TAKEN TO AN INDEPENDENT MECHANIC WHERE THEY ADVISED HIM THAT HE NEEDED TO REPLACE THE FUEL TANK. THE VEHICLE WAS NOT REPAIRED. THE MANUFACTURER WAS CONTACTED AND OFFERED NO ASSISTANCE. THE FAILURE AND CURRENT MILEAGES WERE APPROXIMATELY 54,000.
TL*THE CONTACT OWNS A 2003 MERCEDES BENZ SL55. WHEN THE VEHICLE WAS TURNED ON NOISE WAS NEAR THE BRAKE SYSTEM AND THERE WERE NO WARNING LIGHTS ILLUMINATED. THE VEHICLE WAS TAKEN TO A MECHANIC FOR INSPECTION. THE MECHANIC STATED THAT THE SBC HYDRAULIC SYSTEM WAS INOPERABLE AND THERE WAS NO COMMUNICATION WITH THE PUMP MOTOR. NHTSA RECALL 04V296000, SERVICE BRAKES, HYDRAULIC WAS RELATED TO THE FAILURE; HOWEVER, THE MECHANIC ADVISED HIM TO TAKE THE VEHICLE TO THE DEALER FOR DIAGNOSTIC TESTING AT HIS EXPENSE FOR $150. THE MANUFACTURER WAS NOT NOTIFIED. THE FAILURE MILEAGE WAS 45,600.
DEFECTIVE FUEL TANK BAFFLES. FUEL TANK BAFFLE(S) COME LOOSE AND BOUNCE AROUND INSIDE TANK BANGING THE SIDES OF THE FUEL TANK. *TR
ABC SUSPENSION SYSTEM AND INTERCOOLER PUMP FOR TURBO FAILED ON 2003 SL55 AMG. VERY COMMON PROBLEM ON THESE VEHICLES AS EVIDENCED ON THE MB BOARDS. RECALL SHOULD BE ISSUED. *TR
I WAS HAVING SOME TROUBLE WITH THE BRAKES, I BROUGHT THE CAR BACK INTO THE SHOP 3 TIMES TO LET THEM KNOW THAT THE BRAKES WERE FAILING - ONCE I ALMOST RAN A PEDESTRIAN OVER AS I TRIED TO STOP AND THE VEHICLE BRAKES APPEARED TO NOT WORK AT ALL - THE HYDRAULIC SYSTEM THEY SAY DOES NOTHING. ANOTHER TIME PULLING INTO A PARKING SPACE NO BRAKES AGAIN AND IF IT WEREN'T FOR THE CONCRETE BLOCK I WOULD HAVE RUN INTO THE STORE FRONT. THE LAST TIME WAS AT MY HOME - PULLING INTO THE DRIVEWAY. AFTER BRINGING THE CAR INTO THE MERCEDES DEALER MULTIPLE TIMES WITH THE SAME PROBLEM THEY TOLD ME EVERYTHING WAS FINE UNTIL I WAS OUT ONE NIGHT AND CAME TO A STOP SIGN AND THE BRAKES FAILED AND I WENT INTO A CONCRETE BARRIER. I WISH I HAD VISITED THIS SITE BEFORE THE ACCIDENT HAPPENED - I WOULD RECOMMEND THAT ANYONE WITH A 2003 MERCEDES SL GET RID OF IT - BRING IT BACK TO MERCEDES AND DEMAND A 2004 OR NEWER CAR BEFORE THIS HAPPENS TO YOU. MERCEDES CAME TO INSPECT THE VEHICLE AT THE AUTOBODY SHOP AND WILL NOT RELEASE THEIR FINDINGS TO ME - I AM THINKING OF GETTING A LAWYER INVOLVED. - I HAVE NEVER IN MY LIFE BEEN IN A SITUATION WHERE YOU ARE SO HELPLESS AND MERCEDES KNOWS ABOUT THIS - WHAT A CRIME. *TR
2003 MERCEDES SL-55 ENGINE STALLED SEVERAL TIMES OVER A PERIOD OF TWO WEEKS. *KB
11 of 11 complaints, reproduced as filed.
Reading this record
No unusual pattern of severe incidents in the complaint record.
Complaint counts track how many cars were sold and how long they have been on the road as much as they track quality. A common model from 2013 has had a decade to accumulate reports; a rare one from last year has not. The signal worth weighing is in the severity columns, in whether the same component keeps appearing, and in whether the manufacturer eventually opened a recall for it.
Most recent recall on file: none. Source: NHTSA Office of Defects Investigation.