2004 Mercedes-Benz SL500

THE SUBJECT S-CLASS VEHICLES CONTAIN A COMPRESSED AIR SUSPENSION SYSTEM THAT USES AIR STRUTS ON EACH OF THE FOUR WHEELS IN LIEU OF TRADITIONAL SPRINGS AND SHOCK ABSORBERS.THESE AIR STRUTS USE COMPRESSED AIR TO SUPPORT THE WEIGHT OF THE VEHICLE AND CONTROL RIDE HEIGHT.IN THE EVENT OF THE LOSS OF AIR FROM THE SYSTEM, AN ALERT WILL FLASH ON THE INSTRUMENT CLUSTER WARNING THE DRIVER TO EITHER DRIVE CAREFULLY OR TO STOP THE VEHICLE.THE VEHICLE RIDE HEIGHT CAN BE REDUCED BY AS MUCH AS 105 MM BELOW NORMAL RIDE HEIGHT BEFORE THE FULL LOAD OF THE VEHICLE FOR THAT WHEEL COMES TO REST ON A STEEL ROD, WITH A RUBBER STOP ON THE END, LOCATED IN THE SHOCK ABSORBER.THIS REST-STOP CONDITION IS DESIGNED SUCH THAT THERE IS NO IMPACT ON VEHICLE CONTROL.MERCEDES-BENZ (MBUSA) SUPPLIED VIDEO SHOWING A VEHICLE IN THIS CONDITION OPERATING UNDER SEVERAL DIFFERENT SITUATIONS INCLUDING EVASIVE MANEUVERS DEMONSTRATING THE ABILITY OF THE VEHICLE TO BE CONTROLLED EFFECTIVELY WITH A RIDE HEIGHT REDUCED TO THE MINIMUM.ONLY THOSE COMPLAINTS TO ODI AND MBUSA THAT ALLEGED A STEERING INTERFERENCE DURING A REDUCED RIDE HEIGHT CONDITION WERE COUNTED IN THIS RESUME FAILURE REPORT.SOME COMPLAINTS ALLEGED THAT WITH A REDUCED RIDE HEIGHT AND A STOP NOW WARNING MESSAGE THERE WAS A RUBBING NOISE WHEN TURNING, BUT THE ABILITY TO STEER THE VEHICLE WAS NOT COMPROMISED.A SAMPLING OF WARRANTY CLAIMS SUBMITTED BY MBUSA DID NOT REVEAL ANY INDICATING A LOSS OF CONTROL DUE TO AN AIRMATIC SYSTEM FAILURE.THERE WAS ONE CRASH REPORTED BY MBUSA TO ODI BUT THE INFORMATION AVAILABLE INDICATED THAT IT RELATED TO SUSPENSION SYSTEMS AND IT WAS NOT POSSIBLE TO VERIFY THAT THE INCIDENT WAS RELATED TO AN AIRMATIC SYSTEM FAILURE. FURTHER USE OF AGENCY RESOURCES IN THIS MATTER DOES NOT APPEAR TO BE WARRANTED.THE AGENCY WILL CONTINUE TO MONITOR COMPLAINTS AND OTHER INFORMATION RELATING TO THE ALLEGED DEFECT IN THE SUBJECT VEHICLES AND WILL TAKE FURTHER ACTION IN THE FUTURE IF WARRANTED.THIS PRELIMINARY EVALUATION IS CLOSED.

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 ID

11754971

Incident

Jul 15, 2026

Mileage

62,800 mi

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 ID

11713126

Incident

Jan 24, 2026

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.

NHTSA ID

11518528

Incident

Sep 30, 2021

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

NHTSA ID

11463728

Incident

May 1, 2022

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.

NHTSA ID

11342296

Incident

Jul 22, 2020

Mileage

118,000 mi

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.

NHTSA ID

11331597

Incident

Jan 10, 2020

Mileage

92,000 mi

I EXPERIENCE A STRONG ODOR OF FUEL WHEN ENTERING MY VEHICLE AND WHEN DRIVING THE VEHICLE, ALSO WHEN DRIVING THE VEHICLE I HEART A LOUD THUMPING SOUND COMING FROM THE TRUNK AREA. SOUNDS TO ME AS THOUGH SOMETHING IS FLOATING INSIDE GAS TANK. THIS ODOR HAS SICKENED ME AND HAS SEVERELY UPSET MY STOMACH TO THE POINT THAT I'M UNABLE TO DRIVE MY VEHICLE EXCEPT FOR A SHORT DISTANCE. THE THUMPING SOUND IS CREATED WHEN VEHICLE IS MOVING OR COMING TO A STOP BUT HAPPENS CONTINUOUSLY WHILE DRIVING. *TR

NHTSA ID

11326987

Incident

May 1, 2020

Mileage

88,620 mi

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

NHTSA ID

11208386

Incident

May 1, 2012

Mileage

60,000 mi

Single throttle lift-off clunking noise from the side shaft when moving off (audible at the outboard end). The noise is heard once in each instance when changing direction of travel. Note: Sound file in attachment Cause If the complaint is eliminated by experimentally loosening the outboard collar nut (by 1 turn), the problem is due to cracking of the microweld between the wheel bearing inner race and the joint housing of the side shaft. Note: The collar nut must always be replaced after being loosened. See also LI33.20-P-078406 Remedy Coat contact surface of side shaft with wheel bearing with Molykote paint. To do this, proceed as follows: 1. Remove side shafts 2. Clean contact surface A (see image file in attachment "Outer joint housing before") before coating with Molykote, using "spirit" (free of dust and grease) 3. Coat contact surface A (see image file in attachment "Outer joint housing after") with Molykote and leave to dry for "one hour" in removed condition 4. Reinstall side shafts Note: Before using the antifriction coating (Molykote), stir it or shake it thoroughly for (at least 1 minute).

Complaint There are several types of complaint about noises or poor windshield wiper wiping performance: A: Wiper blades squeaking, chattering, shuddering B: The windshield is not wiped completely (streaking) C: During the downward movement water is pulled back onto the windshield from the A-pillar (Figure 1) D: After windshield cleaning, water keeps spraying onto the windshield for several wipe cycles (Figure 2) A1: The windshield and wiper blades are contaminated with residues from car washing facilities, identifiable by the water beading. The resulting differences in the friction values between the wiper blades and the windshield can excite the wiper blades to vibrate. Note: It is mostly wax residue from the washer system, but also water-repellent nano-particle coating for paint and/or silicone-based washer fluid, that could cause this problem. A partially dry windshield also has different friction values, which can likewise result in squeaking of the wiper blades A2: The wiper blades are worn by mechanical damage (wiper lip damaged by ice or insect debris, or deformed by long periods of disuse). A3: Incorrect angle of incidence of the wiper arms to the windshield. Because of this, the rubber lip of the wiper blade may not flip over at the reversal point. Cause B: B1: Wax/ dirt residues on the windshield B2: Wiper blades deformed or worn B3: Downforce of wiper arm not OK (Figure 3) Cause C: Water is pulled back onto the windshield by the differential pressure created as the wiper arm moves downwards. Cause D: Washer water collects in the fastening of the wiper blade and is blown onto the windshield by the airstream over several wipe cycles. Note and supporting information: Wiper blades are wear parts which, even when "not used" for long periods (kept in park position), may become permanently deformed and damaged. Further stresses on the rubber wiper blade arise due to various environmental influences which progressively change the effectiveness of the rubber wiper blade and accelerate the aging process. Due to the natural aging process and wear, the wiper blades should be replaced twice a year, preferably in Spring and Fall (see operator's manual). Remedy Remedy A: A1: Cleaning entire windshield with A 000 986 40 71. A2: Checking water's flow behavior after windshield has been cleaned (see Video 1). If, after cleaning, there are still areas with water beading, then the cleaning process must be carried out again until a rejection reaction is no longer present. • Note: On the vehicle in the video (Video 1), water still beads on the bottom left of the windshield. The windshield is still not properly clean, even though it appears to be clean. The windshield is only properly clean when there are no more areas on the windshield where water beads. A3: Replace wiper blades with genuine wiper blades. Important: Only exchange wiper blades if windshield no longer has water-repellent areas Note: Replacement of wiper blades is not covered under warranty and can be replaced at the expense of the customer. Remedy B: B1: Clean windshield with intensive cleaner A 000 986 40 71. Important: Do not clean the wiper blades otherwise the graphite coating will be damaged. B2: Replace wiper blades with genuine wiper blades • Note: Replacement of wiper blades is not covered under warranty and can be replaced at the expense of the customer. B3: Check the wiper arm for excessive resistance in the bearing. Restore mobility or replace wiper arm if necessary. Remedy C: Problem inherent in design for which there is no technical remedy. Exception: X204 up to 02/2014. In these vehicles, it is possible to install the design configuration of vehicles as of 02/2014. This includes wiper arms (styled arms) with improved behavior in this respect. It is also necessary to replace the wiper blades because the styled arms feature a Top Lock connection (previously Side Lock).

Complaint Headlamp, front fog lamp leaky or fogged. Cause Fogging of the headlamps is a natural phenomenon, which can occur under certain climatic conditions. It does not lead to any technical impairment of the headlamp. If a pressure compensation diaphragm is fitted in the housing cover, then the lamp unit is a "closed system". Remedy Headlamp: Remedy 1 Clearing fogged/condensed LED headlamps: 1. Drive vehicle into workshop (temperature higher than +18 °C/+64.4 °F) and connect the exhaust extraction. Note: Do not perform an engine wash before the defogging test. 2. Switch off the engine and connect battery support via a charger. 3. Open the hood. 4. Switch on the lights. 5. Leave the vehicle in this state for 60 minutes. 6. Check for formation of condensation, a significant reduction in the formation of condensation must be clearly recognizable (thawing progress). Clearing of fogged/condensed LED headlamps and LED rear lamps on electric vehicles: 1. Drive the vehicle into the workshop (temperature higher than +18 °C/+64.4°F). 2. Connect battery backup via a charger. 3. Open the front-end flap and ensure sufficient ventilation. 4. Switch on the lights. 5. Leave the vehicle in this state for 60 minutes. 6. Check for formation of condensation, a significant reduction in the formation of condensation must be clearly recognizable (thawing progress). Clearing fogged/condensed halogen/xenon headlamps: 1. Drive the vehicle into the workshop (temperature higher than +18 °C/+64.4°F). Note: Do not perform an engine wash before the defogging test. 2. Switch off the engine. 3. Open the hood. 4. Switch off the lights. 5. Leave the vehicle in this state for 60 minutes. 6. Check for formation of condensation, a significant reduction in the formation of condensation must be clearly recognizable (thawing progress). Note: If there is no visible reduction in condensation, check the headlamp for malfunctions. (see Remedy 2) It is not physically possible to defog the headlamps completely. Fogging does not impair the operation or the service life of the headlamp. Note: Only implement Remedy 1 for model series 463 (from model year 2018) and model series 465. Remedy 2 A defective headlamp can be identified as follows: 1. Check the headlamp for external damage and that the cover caps and the diaphragm are correctly seated. 2. Check the electrical connectors of the plugs and pins. 3. Check for leak tightness according to LI82.10-P-078307. The test can only be conducted on headlamps. 4. If the headlamp or the rear lamp has any external damage, replace the component part in accordance with the WIS instructions. Note: External damage to the headlamp/rear lamp or faulty seating of the cover caps does not present a warranty or goodwill case. Note: With headlamps, it is possible to install desiccant packs if the problem occurs repeatedly. • Open ventilation system LI82.10-P-078302 • Closed ventilation system LI82.10-P-078304

Complaint Headlamp, front fog lamp leaky or fogged Cause Fogging of the headlamps is a natural phenomenon, which can occur under certain climatic conditions. It does not lead to any technical impairment of the headlamp. If a pressure compensation diaphragm is fitted in the housing cover, then the lamp unit is a "closed system". Remedy Headlamp: Remedy 1 Clearing fogged/condensed LED headlamps: 1. Drive vehicle into workshop (temperature higher than +18 °C/+64.4 °F) and connect the exhaust extraction. Note: Do not perform an engine wash before the defogging test. 2. Switch off the engine and connect battery support via a charger. 3. Open the hood. 4. Switch on the lights. 5. Leave the vehicle in this state for 60 minutes. 6. Check for formation of condensation, a significant reduction in the formation of condensation must be clearly recognizable (thawing progress). Clearing of fogged/condensed LED headlamps and LED rear lamps on electric vehicles: 1. Drive the vehicle into the workshop (temperature higher than +18 °C/+64.4°F). 2. Connect battery backup via a charger. 3. Open the front-end flap and ensure sufficient ventilation. 4. Switch on the lights. 5. Leave the vehicle in this state for 60 minutes. 6. Check for formation of condensation, a significant reduction in the formation of condensation must be clearly recognizable (thawing progress). Clearing fogged/condensed halogen/xenon headlamps: 1. Drive the vehicle into the workshop (temperature higher than +18 °C/+64.4°F). Note: Do not perform an engine wash before the defogging test. 2. Switch off the engine. 3. Open the hood. 4. Switch off the lights. 5. Leave the vehicle in this state for 60 minutes. 6. Check for formation of condensation, a significant reduction in the formation of condensation must be clearly recognizable (thawing progress). Note: If there is no visible reduction in condensation, check the headlamp for malfunctions. (see Remedy 2) It is not physically possible to defog the headlamps completely. Fogging does not impair the operation or the service life of the headlamp. Note: Only implement Remedy 1 for model series 463 (from model year 2018) and model series 465. Remedy 2 A defective headlamp can be identified as follows: 1. Check the headlamp for external damage and that the cover caps and the diaphragm are correctly seated. 2. Check the electrical connectors of the plugs and pins. 3. Check for leak tightness according to LI82.10-P-078307. The test can only be conducted on headlamps. 4. If the headlamp or the rear lamp has any external damage, replace the component part in accordance with the WIS instructions. Note: External damage to the headlamp/rear lamp or faulty seating of the cover caps does not present a warranty or goodwill case. Note: With headlamps, it is possible to install desiccant packs if the problem occurs repeatedly. • Open ventilation system LI82.10-P-078302 • Closed ventilation system LI82.10-P-078304

Complaint Headlamps leaking or fogged Cause The fogging of the headlamp is a natural phenomenon which can occur under certain climatic conditions. In contrast to a leaky headlamp, physical fogging does not result in a technical impairment of the headlamp. A leak test must be performed to determine if physical fogging exists or if the headlamp is leaky. Remedy In advance, observe LI82.10-P-078301 "Headlamp/front fog lamp leaky or fogged". 1. Prepare headlamp/check for external damage: For headlamps with a closed system • Check the headlamps for any external damage and check also for correct seating of the Gore-diaphragm/correct latching of the cover caps. • If the headlamp exhibits any external damage, replace the headlamp. For headlamps with an open system • Check the headlamps for any external damage and seal off the vent then make sure the cover caps are latched correctly into place. • If the headlamp exhibits any external damage, replace the headlamp. Note: A headlamp with external damage is not a warranty or goodwill case. 2. Leak test of headlamp with overpressure: Connect test adapter to pressure tester. (Figure 1) Check test adapter for leak tightness. To do so, connect plug and coupling (Figure 2) and apply a maximum overpressure of 30 mbar. • The pressure must remain constant. If the pressure does not remain constant, use a new adapter. Seal all the outlet openings using sealing compound and the given diaphragm with the plunger (Figure 3). (Figure 4) • Make allowance for the different headlamp variants here (there are different outlet openings). Check if the headlamp needs to be removed to gain access to the diagnostic socket on the headlamp housing. Plug the adapter onto the diagnostic socket on the headlamp housing. (Figure 5). Apply a maximum of 30 mbar overpressure to the headlamp housing. Note: If the maximum overpressure of 50 mbar is exceeded the headlamp seal will be damaged. • If a pressure drop of less than 10 mbar is measured within 30 seconds, the headlamp is tight and there is natural physical condensation• If a higher pressure drop than 10 mbar is measured within 30 seconds, the headlamp is leaky. Note: The leaky position can be localized with the aid of soap suds. Replace any leaky headlamps. Desiccant packs can be installed for headlamps that are not leaky. Observe the following documents for installation of desiccant packs: • LI82.10-P-078302 Fogged headlamp, desiccant pack installed - open ventilation system • LI82.10-P-078304 Fogged headlamp, desiccant pack installed - closed ventilation system

Complaint Headlamp, front fog lamp leaky or fogged Cause Fogging of the headlamps is a natural phenomenon, which can occur under certain climatic conditions. It does not lead to any technical impairment of the headlamp. If a pressure compensation diaphragm is fitted in the housing cover, then the lamp unit is a "closed system". Remedy Headlamp: Remedy 1 Clearing fogged/condensed LED headlamps: 1. Drive vehicle into workshop (temperature higher than +18 °C/+64.4 °F) and connect the exhaust extraction. Note: Do not perform an engine wash before the defogging test. 2. Switch off the engine and connect battery support via a charger. 3. Open the hood. 4. Switch on the lights. 5. Leave the vehicle in this state for 60 minutes. 6. Check for formation of condensation, a significant reduction in the formation of condensation must be clearly recognizable (thawing progress). Clearing of fogged/condensed LED headlamps and LED rear lamps on electric vehicles: 1. Drive the vehicle into the workshop (temperature higher than +18 °C/+64.4°F). 2. Connect battery backup via a charger. 3. Open the front-end flap and ensure sufficient ventilation. 4. Switch on the lights. 5. Leave the vehicle in this state for 60 minutes. 6. Check for formation of condensation, a significant reduction in the formation of condensation must be clearly recognizable (thawing progress). Clearing fogged/condensed halogen/xenon headlamps: 1. Drive the vehicle into the workshop (temperature higher than +18 °C/+64.4°F). Note: Do not perform an engine wash before the defogging test. 2. Switch off the engine. 3. Open the hood. 4. Switch off the lights. 5. Leave the vehicle in this state for 60 minutes. 6. Check for formation of condensation, a significant reduction in the formation of condensation must be clearly recognizable (thawing progress). Note: If there is no visible reduction in condensation, check the headlamp for malfunctions. (see Remedy 2) It is not physically possible to defog the headlamps completely. Fogging does not impair the operation or the service life of the headlamp. Remedy 2 A defective headlamp can be identified as follows: 1. Check the headlamp for external damage and that the cover caps and the diaphragm are correctly seated. 2. Check the electrical connectors of the plugs and pins. 3. Check for leak tightness according to LI82.10-P-078307. The test can only be conducted on headlamps. 4. If the headlamp or the rear lamp has any external damage, replace the component part in accordance with the WIS instructions. Note: External damage to the headlamp/rear lamp or faulty seating of the cover caps does not present a warranty or goodwill case. Note: With headlamps, it is possible to install desiccant packs if the problem occurs repeatedly. • Open ventilation system LI82.10-P-078302 • Closed ventilation system LI82.10-P-078304