43 of the
308 complaints filed about the Mercedes Benz SL500
are about the braking system —
14% of everything owners reported.
The worst model year for it is 2003.
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.
NHTSA complaint #11754971 — an unverified report by a vehicle owner.
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!".
NHTSA complaint #11713126 — an unverified report by a vehicle owner.
The contact owns a 1999 N/A Mercedes-Benz SL500. The contact purchased the rear brake rotors and pads from R1 Concepts, who sells auto parts on Amazon. When the contact installed the brake parts, the rotors could not be adjusted since the rotors were missing the opening that needed to be pre-drilled. The contact stated that when the rear brakes were adjusted, the defect was found. In addition, the contact stated that while parking the vehicle and setting the parking brake, there was an abnormal sound coming from the vehicle. The contact stated that the parking brake failed to engage. After several attempts, the parking brake was set. No warning lights were illuminated. A dealer was not contacted, and the vehicle was not diagnosed or repaired. The contact stated that the companies were selling defective products. The manufacturer was made aware of the failure but denied assistance. The failure mileage was unknown.
NHTSA complaint #11691658 — an unverified report by a vehicle owner.
The contact owns a 2003 Mercedes-Benz SL500. The contact stated while driving 40 MPH, the brake pedal was depressed however, the vehicle failed to respond as needed. The contact depressed the brake pedal firmly however, the vehicle failed to respond. The parking brake was activated however, the vehicle failed to respond as designed. The contact was however able to pull over and eventually the vehicle came to a complete stop. The vehicle was towed. The dealer and the manufacturer were contacted and stated that the VIN was not included in NHTSA Campaign Number: 05V133000 (Service Brakes, Hydraulic). The failure mileage was 126,000. The consumer stated the part put on the vehicle for the recall was a defective part and not installed correctly.
NHTSA complaint #11474801 — an unverified report by a vehicle owner.
The contact owns a 2005 Mercedes-Benz SL500. The contact stated that while driving from a complete stop, the brake warning light and other unknown warning lights illuminated. The contact stated that he lost control of the vehicle but did not provide further information. The contact stated that while driving at 15 MPH, the brake pedal was depressed but failed to respond. The warning message "Reduced Braking Power, Depress Brake Pedal Fully" and another message advising the contact to take the vehicle to the nearest service station illuminated. The contact continued to depress the brake pedal all the way to the floorboard, but the brake pedal would not respond. The contact stated that the vehicle stopped independently at some point. The vehicle was towed to the dealer who test drove the vehicle and diagnosed that no issues were found as no warning lights were illuminated. The dealer also informed the contact that they could not repair the vehicle under an unknown extended warranty for the sensotronic brake control system replacement as his vehicle was not under the extended warranty. The manufacturer was notified of the failure and confirmed the information from the dealer. Later on, the manufacturer followed up with the contact and confirmed that his vehicle was under the sensotronic brake control system replacement extended warranty; however, the dealer would need to diagnose the vehicle at his expense before they would cover the repair. The vehicle was not repaired. The failure mileage was approximately 22,000.
NHTSA complaint #11447471 — an unverified report by a vehicle owner.
TL* THE CONTACT OWNS A 2006 MERCEDES BENZ SL500. THE CONTACT STATED THAT WHILE OPERATING THE VEHICLE, THE ABS WARNING LIGHT REMAINED ILLUMINATED. THE VEHICLE WAS TAKEN TO ASTORG MOTOR COMPANY LOCATED AT 2908 7TH ST, PARKERSBURG, WV 26102, WHO REPLACED THE ABS BRAKE COMPRESSOR. LATER WHILE DRIVING, THE MESSAGE STOP PUMP BRAKES, WAS DISPLAYED ON THE INSTRUMENT PANEL. THE VEHICLE WAS TOWED BACK TO THE SAME DEALER. THE CAUSE OF THE FAILURE WAS NOT YET DETERMINED. THE MANUFACTURER WAS NOTIFIED OF THE FAILURE. THE FAILURE MILEAGE WAS 68,000.
NHTSA complaint #11378227 — an unverified report by a vehicle owner.
TL* THE CONTACT OWNS A 2005 MERCEDES-BENZ SL500R. WHILE DRIVING 50 MPH, THE BRAKE PEDAL WAS DEPRESSED TO THE FLOORBOARD, BUT FAILED TO STOP THE VEHICLE. THE CONTACT HAD TO APPLY THE EMERGENCY BRAKE TO STOP THE VEHICLE. THE CONTACT STATED THAT SEVERAL UNKNOWN WARNING INDICATORS ILLUMINATED. THE VEHICLE WAS TOWED TO MERCEDES-BENZ OF ORLAND PARK (LOCATED AT 8430 W 159TH ST, ORLAND PARK, IL 60462, (708) 460-0400) WHERE IT WAS DIAGNOSED WITH A LOW BATTERY. THE VEHICLE WAS NOT REPAIRED. THE MANUFACTURER WAS NOT NOTIFIED. THE FAILURE MILEAGE WAS 48,000.
NHTSA complaint #11240643 — an unverified report by a vehicle owner.
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).'
NHTSA complaint #11208386 — an unverified report by a vehicle owner.
ON 04/14/2019 WHILE DRIVING, RED DASH WARNING LIGHTS CAME ON WARNING OF LOST BRAKING AND TO STOP. AT THE SAME TIME TWO SEPARATE WARNING SOUNDS FILLED THE CARS CABIN. I TRIED THE BRAKES, NO RESPONSE, I DOWN SHIFTED, AND STOOD BOTH FEET ON BRAKES AND FINALLY SHIFTED TO NEUTRAL TO COME TO COMPLETE STOP. TURNED CAR OFF WARNING SIGN AND WARNING SOUNDS CONTINUED AFTER ENGINE WAS TURNED OFF. OPENED HOOD, CLICKING AND WURLING SOUNDS WERE COMING FROM THE SBC BRAKING SYSTEM. CALL M/B THE FOLLOWING DAY AND HAD VEHICLE TOWED TO NEAREST M/B DEALER. DEALER FOUND NO FAULTS. AFRAID TO DRIVE. DEALER WILL NOT DO ANY WORK ON CAR W/O CODES TO VERIFY PROBLEM.
NHTSA complaint #11196708 — an unverified report by a vehicle owner.
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
NHTSA complaint #11173505 — an unverified report by a vehicle owner.
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
NHTSA complaint #11173505 — an unverified report by a vehicle owner.
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.
NHTSA complaint #11142891 — an unverified report by a vehicle owner.
2006 SL 500. CONSUMER WRITES IN REGARDS TO SBC WARNING CLUSTER ILLUMINATED AND BRAKE FAILURE. *LD THE CONSUMER STATED THE BRAKES FAILED WHILE DRIVING CAUSING THE VEHICLE TO ROLL THROUGH AN INTERSECTION. THE CONSUMER LIMPED THREE BLOCKS HOME. FAULT CODES C25DS, C26DE, C26BB, AND C233D IN THE SBC SYSTEM.
NHTSA complaint #11082909 — an unverified report by a vehicle owner.
2005 MERCEDES SL500. CONSUMER WRITES IN REGARDS TO VEHICLE BRAKE SYSTEM FAILURE WHILE DRIVING. *SMD THE CONSUMER STATED WITHOUT WARNING THE SBC PUMP WARNING LIGHT APPEARED AND THE BRAKES FAILED. THE SBC PUMP NEEDED TO REPLACED. THE VEHICLE WAS REPAIRED.
NHTSA complaint #10846510 — an unverified report by a vehicle owner.
I PURCHASED THIS VEHICLE IN 2014. MY BRAKES COMPLETELY WENT OUT WHILE DRIVING JANUARY 1 2018. I WAS ATTEMPTING TO STOP AT AN INTERSECTION WHEN THE THE VEHICLE WOULD NOT STOP WITH ONCOMING TRAFFIC ON BOTH SIDES COMING TOWARDS ME. I IMMEDIATELY PRESSED THE ACCELERATOR AND SPED THROUGH THE INTERSECTION TO AVOID AN ACCIDENT....ABSOLUTELY TERRIFYING AND WITHOUT ANY WARNING WHATSOEVER. BECAUSE THE DEALERSHIP WAS CLOSED I WAS UNABLE TO SEEK SERVICE THAT DAY. I CALLED MERCEDES OF RICHMOND VA BEING THAT WAS THE CLOSEST DEALERSHIP WHERE I WAS VISITING AT AT THE TIME. UNFORTUNATELY I COULD NOT GET AN APPOINTMENT UNTIL JANUARY 3RD. I HAD IT TOWED THAT MORNING AND THEY CAME BACK HOURS LATER NOTIFYING ME IT WAS IN FACE THE SBC SYSTEM WHICH NEEDED TO BE REPLACED AT THE COST OF $2006. I WAS OUTRAGED LEARNING THAT MBUSA KNEW OF THIS ISSUE NHTSA CAMPAIGN NUMBER 04V296000 IN JUNE 2004 BUT CLOSED IT OUT IN DECEMBER 2013. I DID NOT PURCHASE THE VEHICLE UNTIL 2014. I ASKED IF THERE WAS ANYTHING THEY COULD DO TO ASSIST ME AS ONE OF THE ASSOCIATES INFORMED ME ABOUT "GOOD WILL" SERVICE WHERE THEY MIGHT CONSIDER MY SITUATION AND HELP. I WAS AGAIN EXTREMELY DISAPPOINTED TO LEARN THEY WOULD ONLY ASSIST WITH $300 AS WE HAVE 2 MERCEDES AND HAVE INCURRED THOUSANDS OF DOLLARS IN KNOWN REPAIR ISSUES OF THE FEW YEARS. I AM ASKING THAT MBUSA ACCEPT THE COST OF THIS REPAIR AS IT WAS A KNOWN ISSUE THAT THEY WERE REPLACING AT NO COST TO OWNER. I HAVE 131,000 MILES ON THE CAR WHICH IS UNDER MILEAGE FOR THAT YEAR. THEY TOLD ME TO ASK MERCEDES IF THEY WOULD CONSIDER ASSISTING IN ANY WAY BUT THEY SAID THERE WAS NOTHING THEY COULD DO.
NHTSA complaint #11058517 — an unverified report by a vehicle owner.
WHILE DRIVING MY MERCEDES BENZ 2003 SL500 THE BRAKES BECAME DISABLED WITHOUT WARNING. IT WAS A TERRIFYING EXPERIENCE. THE FIRST MERCEDES DEALER I PHONED TOLD ME THAT THERE WAS NO KNOWN SAFETY RECALLS FOR THE BRAKES. THE SECOND MERCEDES DEALER THAT I CONTACTED INFORMED ME ABOUT 2 RECALLS IN 2004 AND 2005. I PHONED THE MERCEDES BENZ USA HEADQUARTERS AND SPOKE TO A CASE MANAGER WHO TOLD ME THAT MERCEDES' RESPONSIBILITY WITH THIS SAFETY ISSUE EXPIRED IN 2012. HOW CAN A SAFETY ISSUE SUCH AS HAVING NO BRAKES WHILE DRIVING EXPIRE? HOW CAN A CORPORATION BE ALLOWED TO WALK AWAY FROM THIS TYPE OF POTENTIALLY DEADLY SAFETY ISSUE? THIS IS A WELL DOCUMENTED SAFETY ISSUE WITH THIS CAR.
NHTSA complaint #11023809 — an unverified report by a vehicle owner.
WHILE DRIVING THE CAR IN TOWN ON CITY STREETS THE SBS BRAKE SYSTEM FAILED AS I CAME TO A TURN LEAVING ME WITH NO BRAKE RESPONSE EVEN THOUGH THE DEALER SAYS IT WAS SUPPOSED TO HAVE HYDRAULIC BACK-UP TO STOP THE CAR. I WAS ABLE TO COAST AND STOP THE CAR ONLY WITH THE EMERGENCY HAND BRAKE. THE SBS SYSTEM HAS BEEN RECALLED TWICE BY THE FACTORY BUT THERE IS STILL SOMETHING VERY WRONG WHEN A MODERN CAR HAD NO BACK-UP SYSTEM. THESE CARS ARE DANGEROUS! LUCKILY FOR ME THERE WAS NO ACCIDENT AND I HAD THE CAR TOWED TO THE DEALER AND IT IS BEING REPAIRED.
NHTSA complaint #10969321 — an unverified report by a vehicle owner.
I OWN A 2003 MERCEDES BENZ SL 500 AND REPLACED THE HYDRAULIC PUMP IN 2014 FOR $6400.00. THE CAR WOULD DROP LOW (ON ONE SIDE IF PARKED FOR A FEW HOURS). TODAY, JANUARY 5, 2017 - THE IDENTICAL PROBLEM HAPPENED AGAIN. WHILE DRIVING, I HEARD A LOUD BURSTING SOUND AND THEN HYDRAULIC FLUID BEGAN SEEPING OUT ALSO, THE ABC RED DASH LIGHT ILLUMINATED STATING THAT THE CAR IS "TOO LOW TO DRIVE". I MANAGED TO SLOWLY DRIVE HOME (WITHOUT POWER STEERING). THIS IS A HUGE DEFECT IN MERCEDES BENZ TECHNOLOGY AND MANUFACTURING - A CLASS ACTION LAWSUIT IS ABSOLUTELY NECESSARY. THIS VEHICLE IS DEFECTIVE AND DANGEROUS TO OPERATE. ALSO, CONSUMERS SHOULD NOT SPEND THOUSANDS UPON THOUSANDS OF DOLLARS ON DEFECTIVE PARTS. BY THE WAY, THIS VEHICLE HAS ALWAYS BEEN SERVICED BY MERCEDES BENZ DEALERSHIP TECHNICIANS. I WOULD APPRECIATE ANY ADDITIONAL INFORMATION OR SUPPORT FROM THE NHTSA AS I PURSUE VIABLE RECOURSE OPTIONS. THANK YOU!
NHTSA complaint #10940037 — an unverified report by a vehicle owner.