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.
The worst 2003 Mercedes Benz SL55 problems
Ranked by number of owner complaints. Mileage and cost come from what owners wrote.
- Fuel system3
- Brakes2
- Electrical2
- Engine2
- Suspension1
Problems by type
Tap a problem to see which part fails, at what mileage and in which other years.
- Fuel system3
- Brakes2
- Electrical2
- Engine2
- Suspension1
- Transmission1
Recalls
No recalls on record for this model year.
Defect investigations
Air suspension system failure
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.
PE07042
Technical service bulletins for the 2003 Mercedes Benz SL55 42
Bulletins tell dealers how to fix known problems. A warranty extension means the manufacturer pays for that repair for longer.
- Repeat workshop visit for vehicle vibration while braking from 60MPH. NOTE: Although the symptom is...
- Clanking noise from the area of the speakers in the doors
- Single throttle lift-off clunking noise from the side shaft when moving off (audible at the outboard end)
- There are several types of complaint about noises or poor windshield wiper wiping performance: A: Wiper...
- Headlamp, front fog lamp leaky or fogged
- Headlamp, front fog lamp leaky or fogged
- Headlamps leaking or fogged
- Single throttle lift-off clunking noise from the side shaft when moving off (audible at the outboard end)
- Headlamp, front fog lamp leaky or fogged
- During a phone call, the called party has difficulty understanding/cannot understand the driver, or...
What 2003 Mercedes Benz SL55 owners say
Most recent owner complaints, unedited.
It 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.
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. The federal safety agency 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.
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.
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.
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Questions about the 2003 Mercedes Benz SL55
Is the 2003 Mercedes Benz SL55 reliable?
Owners have filed 11 complaints about the 2003 Mercedes Benz SL55, 3.7 times a typical SL55 model year.
What is the most common problem with the 2003 Mercedes Benz SL55?
Fuel and propulsion system, with 3 complaints. Next is brakes (2).
How many recalls does the 2003 Mercedes Benz SL55 have?
No recalls on record.
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