2004 Mercedes-Benz SL500 Problems

TL* THE CONTACT OWNS A 2004 MERCEDES-BENZ SL500. THE CONTACT STATED ON VARIOUS OCCASIONS WHILE HIS VEHICLE WAS STATIONERY AND IN PARK, EITHER THE RIGHT SIDE OR THE LEFT SIDE OF THE VEHICLE WOULD RAISE UP THEN DESCEND TO GROUND OVER A THIRTY SECOND PERIOD INDEPENDENTLY WITHOUT WARNING. THE CONTACT ALSO STATED THAT THE HYDRAULIC FLUID LEAKED OUT OF THE ENGINE. THE VEHICLE HAD YET TO BE TAKEN TO A DEALER TO BE DIAGNOSED OR SERVICED FOR THE FAILURE. UPON INVESTIGATION, THE CONTACT LINKED HIS FAILURE TO NHTSA CAMPAIGN NUMBER :08V405000 (SUSPENSION) HOWEVER, THE VIN WAS NOT INCLUDED IN THE RECALL. THE MANUFACTURER HAD YET TO BE NOTIFIED OF THE FAILURE. THE VEHICLE HAD YET TO BE REPAIRED. THE FAILURE MILEAGE WAS APPROXIMATELY 92,000.

THE VEHICLE HAS A BRACKET ON TOP OF THE GAS TANK THAT COMES DISENGADED AND CAUSES THIS DISTINCTIVE NOISE WHICH SOUNDS LIKE SOMETHING SWINGING AND TAPPING AGAINST THE GAS TANK AND I HAS TO HAPPEN A LOT DUE TO EVERY SERVICE I HAVE BEEN ASKED ABOUT THE PROBLEM. IT ALSO HAS TO BE SOMETHING WITH MULTIPLE VEHICLES DUE TO ONLINE MERCEDES OWNERS ARE HAVING THE SAME PROBLEM. THE SOUND IS REALLY DISTURBING AND I WOULD LIKE AN ANSWER AS TO WHAT TO DO. THANKS [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6).' *PM

The contact owns a 2004 Mercedes-Benz SL500. The contact stated that after starting the vehicle, the message "Brakes Reached Historic Threshold" was displayed, which indicated that the brake control unit had malfunctioned. Additionally, while depressing the brake pedal, the brake pedal was spongy, causing the stopping distance to become extended. The vehicle was taken to the local dealer and was diagnosed with brake control unit failure. The contact was informed that the brake control unit needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure, but no assistance was provided. The contact stated that a 25-year warranty for the failure was previously issued by the manufacturer that was associated with the failure, but was not honored. The failure mileage was 62,800.

Question 1: The Sensotronic Brake Control (SBC) unit, which is a high-pressure "brake-by-wire" hydraulic system. Component A7/3. The component is currently installed in the vehicle and is available for inspection. Question 2: The vehicle experienced a sudden, catastrophic loss of hydraulic brake pressure while in operation. This failure required extreme physical force on the pedal and significant increase in stopping distance. The vehicle is currently in my garage with chocked wheels until I figure out what's next. A couple days ago, I had the car at a dealer and requested a review of this system and they released the car back to me stating the system status was, "OK" despite me stating to the dealer that the safety-monitoring counter was found to be at 0 on a 63,000-mile car. In all of my research, I believe this "silenced" the vehicle's ability to provide a timely service warning (Code C249F) before total hydraulic failure occurred. Question 3: Mercedes-Benz of Denver performed a diagnostic on January 21, 2026. While the dealer initially claimed the system was "OK," the total failure occurred within 72 hours of their inspection. The reason it was at Benz of Denver is because my independent mechanic confirmed the 0 actuation count which was suspicious to me. I wanted to understand the mechanical integrity of the newly purchased vehicle. Question 4: Yes, inspected by an authorized Mercedes-Benz dealership technician on January 21, 2026. Question 5: To my knowledge there were no mechanical symptoms prior to the red screen however, I cannot confirm or deny that as I had driven less than 1000 miles since I purchased the vehicle. I have no concept of how the braking "should have" felt. The only "symptom" was the technical data anomaly (the 0 actuation count) flagged by an independent shop, which I can attest the dealer refused to investigate fully. On January 24th, 2026, the RED dashboard warning appeared: "Reduced Brake Effect - Start Engine!".

On many 2003 and 2004 models. Broken fuel tank baffle inside fuel tank. This is well documented and could possibly cause explosion.

ON JULY 22, 2020 THE VEHICLE (2004 MERCEDES-BENZ SL500 (R230)BEGAN MAKING A LOUD BANGING NOISE IN THE REAR WHEN STOPPING AND TURNING. I DELIVERED THE VEHICLE TO A LOCAL SHOP WHERE THE VEHICLE WAS DIAGNOSED AS HAVING A BROKEN BAFFLE IN THE FUEL TANK. THE ONLY SOLUTION IS TO REPLACE THE ENTIRE FUEL TANK. MANY OTHER OWNERS OF THIS MODEL HAVE EXPERIENCED THE SAME ISSUE AND IS CLEARLY A MANUFACTURER DEFECT; THIS CANNOT BE CAUSED BY EXCESS WEAR ON THE VEHICLE. BECAUSE THERE IS NOW A LARGE SECTION OF THE FUEL TANK FREELY SWINGING INSIDE, THERE IS A CHANCE THAT THIS COULD CAUSE A SPARK AND SUBSEQUENT EXPLOSION. I CANNOT SAFELY DRIVE THIS VEHICLE UNTIL THE FUEL TANK IS REPLACED AT A VERY LARGE COST. THIS MODEL SHOULD HAVE BEEN RECALLED WHEN THIS ISSUE WAS FIRST COMING TO LIGHT OVER 15 YEARS AGO.

The 2003-2006 R230 series seem to have a problem with the BCM (Battery Control Module) as start an electrical fire in the trunk. Very common issue and a safety hazard - this is what happened with my car. Vehicle has dual battery, starter in front, convenience battery in trunk and fuses that operate at 130 Amps - the BCM capacitors and circuit board age and at some point can no longer handle the high current and catch fire.

I SUBMITTED VIA FAX EARLIER THIS WEEK A FORMAL LETTER TO MR. EXLER THE PRESIDENT & CEO OF MBUSA AND, CC'D MR. KING OF THE NHTSA THAT INCLUDED INFORMATION ABOUT KNOWN CRITICAL SAFETY ISSUED THESE VEHICLES HAD PRIOR TO MBUSA IMPORTING THEM TO THE UNITED STATES. MBUSA FAILED TO DISCLOSE THESE KNOWN ISSUES AND, CHOSE TO IMPORTATION THESE VEHICLES VIOLATING VEHICLE IMPORTATION RULES. YESTERDAY-JANUARY 31, 2019 I RECEIVED A CALL FROM A REPRESENTATIVE OF MBUSA STATING HE WAS CALLING ON BEHALF OF MR. EXLERS OFFICE CONCERNING MY LETTER. I WILL NOT BE INTIMIDATED BY MBUSA WHILE SEEKING THE TRUTH ON WHY MBUSA ALLOWED THESE VEHICLES TO ENTER THE USA KNOWING THESE CRITICAL SAFETY ISSUES EXISTED WHILE MISLEADING CONSUMERS AND, THE NHTSA. ON JANUARY 21, 2019 MY VEHICLE HAD WHAT IS DESCRIBED BY MBUSA AS A CATASTROPHIC FAILURE WHEN THE ENTIRE BRAKE SYSTEM FAILED. THIS FAILURE COULD HAVE KILLED ME - AND, OTHER MOTORIST. MBUSA HAS REPLACED THE SBC UNIT AT LEAST 6 TIMES AND, STILL THE ISSUE AND, OTHER PERSIST. THE VEHICLE HAS BEEN DRIVEN ON AVERAGE 4,000 MILES ANNUALLY. HOW MANY FAILURES MUST HAPPEN BEFORE MBUSA IS FULLY INVESTIGATED? THEY REFUSED TO PROVIDE ME ANY INFORMATION ON THE VEHICLES EXCEPT THE 4 YEAR WARRANTY PERIOD. ONCE I COMPLETE MY RESEARCH ON THESE VEHICLES I WILL SUBMIT MY FINDINGS TO THE NHTSA & MS. KING

DUE TO DETERIORATION OF THE WIRING HARNESS CONNECTION OR FAILURE OF THE HYDRAULIC PUMP, THE SENSOTRONIC BRAKE CONTROL (SBC) SYSTEM MAY DEFAULT TO THE HYDRAULIC BACK-UP MODE. IN THE BACK-UP MODE, THE DRIVER HAS BRAKING POWER SUFFICIENT TO STOP THE VEHICLE, BUT GREATER BRAKE PEDAL PRESSURE IS REQUIRED AND BRAKE PEDAL TRAVEL WILL BE NOTICEABLY LONGER. DEALERS WILL INSTALL A BRACKET AND REPLACEMENT GROUND WIRE TO THE SBC PUMP UNIT ON ALL AFFECTED VEHICLES. ADDITIONALLY, DEALERS WILL INSPECT AND REPLACE THE SSC PUMP UNIT IN CERTAIN SL MODELS. THE MERCEDES-BENZ RECALL NUMBERS ARE 2005070007 AND 2005110001. RESEARCH SHOWS ONLY 59% OF THE 100% REQUIRED RECALL WAS DONE PROPERLY BY AN AUTHORIZED DEALER. THIS ISSUE WAS NOT DISCLOSED WHEN I PURCHASED THIS CAR AND, THE REQUIRED WORK WAS NOT DONE AND, MERCEDES SAID THE 60 DAYS FROM RECALL HAD PASSED - YET THE REPORTS SENT TO NHTSA BY MERCEDES BENZ APPEARS TO BE FALSE DATA - THIS SHOULD BE INVESTIGATED.

I LIVE IN TEXAS AND MY MERCEDES WENT INTO LIMP MODE AT A RED LIGHT. I CAN NOT GET MY TRANSMISSION REPAIRED ANYWHERE ELSE BECAUSE THEY HAVE MADE IT IMPOSSIBLE FOR ANY OTHER SHOPS TO BE ABLE TO SERVICE THIS SPECIFIC TRANSMISSION. THEY TELL ME AND I QUOTE "WE ARE UNABLE TO WORK ON THIS TRANSMISSION BECAUSE IT REQUIRES SPECIAL TOOLS WHICH ONLY MERCEDES DEALERSHIP CARRY SO YOU WILL HAVE TO TAKE IT TO THEM, SORRY" PLEASE, PLEASE, PLEASE RECALL THIS TRANSMISSION!!! ANOTHER TIME I WAS DIVING DOWN THE HWY DOING 70MPH WHEN THE ABC TOO LOW DASH LIGHT CAME ON AS WELL AS MY CAR DROPPING 2 INCHED TO THE GROUND AS I WAS DRIVE 70MPH PLUS I LOST CONTROL OF STEERING. AND ONCE AGAIN NO ONE COULD WORK ON IT BECAUSE IT REQUIRES SPECIAL TOOLS. AND THE ONE PLACE THAT COULD SAID THEY WERE MERCEDES BENZ CERTIFIED. AFTER HAVING MY CAR 3 DAYS AND PAYING $125 FOR A DIAGNOSTIC TEST. I WAS TOLD IT WAS GOING TO BE $5000+ TO FIX. LONG STORY SHORT I PAYED THE CAR LOT WHERE I BOUGHT IT FROM $3587.00 TO FIX IT .

DRIVING ON FREEWAY AND HIT BUMP ON FREEWAY THE ABC LIGHTS COME ON VECHICLE HARD TO COTROL HERE RUBBING , VEHICLE TO LOW FLASHES WENT STRAIGHT TO DEALER. *TR

ADDENDUM INFO TO ORIGINAL COMPLAINT #10308437 SHOWS THAT MB SERVICE ADVISOR J. STEACH ADVISED M .B. NOT RESPONSIBLE AS DRIVER SHOULD "MISS" POTHOLES. ENGINEERING ANALYSIS SHOWS THAT IT IS NOT POSSIBLE FOR DRIVER TO STEER AROUND POTHOLES. AT 70MPH MB SL500 TRAVELS 103 FT/SEC AND IT IS NOT POSSIBLE TO OBSERVE THE POTHOLE HAZARD AND CATEGORIZE AS SAFETY RISK AT SPEEDS OF 70MPH(103FT/SEC) REACT PHYSIOLOGICALLY AND ACTUATE STEERING SYSTEM -ALL IN LESS THAN ONE SECOND-ONE HALF SECOND EACH FOR HUMAN RESPONSE AND SAME FOR MECHANICAL ACTUATION-INSUFFICIENT TIME TO AVOID POT HOLE HIT. DARK OR LOW LIGHT CONDITIONS RENDER POTHOLE MISS IMPOSSIBLE. IN ANY CASE, THE IMPROPERLY ENGINEERED SOFT LOW STRENGTH ALLOY WHEEL DESIGN LEADS ANY PRUDENT VEHICLE DRIVER INTO A CRASH TRAP. WHEEL,TIRE, SUSPENSION DAMAGE EVIDENT-NEEDS CORRECTED IMMEDIATELY AT EXPENSE OF MERCEDEZ-BENZ.. WIFE WHIPLASH DUE TO SEVERE ABRUPT UNANTICIPATED FORCES IN BRINGING VEHICLE TO SAFE STOP. I HAVE NECK SORENESS AND AGGRAVATION OF PREVIOUS NECK INJURY LIKELY. *TR

I LIVE IN TEXAS AND MY MERCEDES WENT INTO LIMP MODE AT A RED LIGHT. I CAN NOT GET MY TRANSMISSION REPAIRED ANYWHERE ELSE BECAUSE THEY HAVE MADE IT IMPOSSIBLE FOR ANY OTHER SHOPS TO BE ABLE TO SERVICE THIS SPECIFIC TRANSMISSION. THEY TELL ME AND I QUOTE "WE ARE UNABLE TO WORK ON THIS TRANSMISSION BECAUSE IT REQUIRES SPECIAL TOOLS WHICH ONLY MERCEDES DEALERSHIP CARRY SO YOU WILL HAVE TO TAKE IT TO THEM, SORRY" PLEASE, PLEASE, PLEASE RECALL THIS TRANSMISSION!!! ANOTHER TIME I WAS DIVING DOWN THE HWY DOING 70MPH WHEN THE ABC TOO LOW DASH LIGHT CAME ON AS WELL AS MY CAR DROPPING 2 INCHED TO THE GROUND AS I WAS DRIVE 70MPH PLUS I LOST CONTROL OF STEERING. AND ONCE AGAIN NO ONE COULD WORK ON IT BECAUSE IT REQUIRES SPECIAL TOOLS. AND THE ONE PLACE THAT COULD SAID THEY WERE MERCEDES BENZ CERTIFIED. AFTER HAVING MY CAR 3 DAYS AND PAYING $125 FOR A DIAGNOSTIC TEST. I WAS TOLD IT WAS GOING TO BE $5000+ TO FIX. LONG STORY SHORT I PAYED THE CAR LOT WHERE I BOUGHT IT FROM $3587.00 TO FIX IT .

THE ABC VEHICLE HEIGHT CONTROL SYSTEM CAUSED THE CAR TO DROP VERY CLOSE TO THE GROUND MAKING THE CAR UNDRIVEABLE, HOWEVER AFTER PULLING TO THE SIDE OF THE ROAD AND ALLOWING THE CAR TO SIT, THEN RE STARTING THE CAR WENT UP TO ITS NORMAL HEIGHT, WHAT IF I WAS IN THE EXPRESSWAY? *TR

THE AUTOMATIC TRANSMISSION FAILED TO UPSHIFT BEYOND THIRD GEAR WHILE DRIVING DOWN HIGHWAY. COULD ONLY GO 30MPH AS REVS HIGH. HAD TO TAKE VEHICLE TO DEALER TO REPAIR TRANSMISSION. ONLY 39,000 MILES ON CAR. NOT ABUSED. *TR

I WAS DRIVING IN HEAVY BUMPER TO BUMPER RUSH HOUR TRAFFIC WHEN THE CARS IN FRONT APPROACHED THE RED LIGHT I BEGUN TO APPLY BRAKES AND MY BRAKES WOULD NOT RESPOND UNTIL I STOOD UP ON THE BRAKES AND AS A RESULT I REAR ENDED THE VEHICLE IN FRONT OF ME. LUCKILY NO ONE WAS INJURED. I CARRIED THE CAR TO THE MERCEDES AUTHORIZED DEALERSHIP IN BEVERLY HILLS AND THE PROBLEM WAS DIAGNOSED A ABS PUMP FAILURE AND THEY STATED THAT THERE WAS A RECALL AND THE PREVIOUS OWNER CARRIED IT IN, THEREFORE, I HAD TO PAY FOR THE REPLACEMENT. THEN ON OR ABOUT SEPT 18, THE ABC LIGHT CAME ON AND THE FRONT SUSPENSION FAILED CAUSING THE CAR TO DROP TOO LOW TO SAFELY DRIVE.

TL* THE CONTACT OWNS A 2004 MERCEDES BENZ SL 500. THE CONTACT STATED THAT THE ACTIVE BODY CONTROL WAS LEAKING FLUID NEAR THE ENGINE. THE VEHICLE WAS TAKEN TO THE DEALER WHERE THE CONTACT WAS ADVISED TO HAVE THE ACTIVE BODY CONTROL REPLACED. THE CONTACT REFERENCED NHTSA CAMPAIGN ID NUMBER: 07V263000 (ENGINE AND ENGINE COOLING) PERTAINING TO THE CL CLASS MODEL BUT THE ACTIVE BODY CONTROL COMPONENT WAS THE SAME IN THE SL CLASS MODELS. THE CONTACT BELIEVED THE VEHICLE WAS UNSAFE TO DRIVE. THE FAILURE MILEAGE WAS 74,000.

DRIVING ON FREEWAY AND HIT BUMP ON FREEWAY THE ABC LIGHTS COME ON VECHICLE HARD TO COTROL HERE RUBBING , VEHICLE TO LOW FLASHES WENT STRAIGHT TO DEALER. *TR

"TAKATA RECALL" 1. THE TOTAL BODY OF MY 2004 SL MERCEDES BENZ SUDDENLY COLLAPSED WITHOUT WARNING TO WITHIN 3 INCHES FROM HI-WAY WHILE TRAVELING APPROXIMATELY 50 MILES AN HOUR CAUSING THE WHEELS TO DRAG AGAINST THE UNDERCARRIAGE AND DAMAGE TO FRONT BUMPER PREVENTING ME ME TO STEER FREELY WHILE FLUID FROM THE RUPTURED ABC VALVE LINE APPARENT SPRAYED ON TO THE ENGINE. THE RED ABC LIGHT CAME ON SAYING STOP TO LOW TO DRIVE FOLLOWED BY RED SRS LIGHT (SAFETY RESTAINT SYATEM/ AIR BAGS)