AI Damage2009 Mercedes-Benz SL 550 reliability: common problems
Owners of the 2009 Mercedes-Benz SL 550 filed 15 complaints with NHTSA, most often about service brakes and tires. Details by component below, with sources.
Key figures
- Owner complaints
- 15
What fails most often
- 1 Service brakes 40% of all complaints
- 2 Tires 33% of all complaints
- 3 Wheels 27% of all complaints
- 4 Electrical system 20% of all complaints
- 5 Structure 13% of all complaints
- Service brakes: 6 complaints (40% of all).
- Tires: 5 complaints (33% of all).
- Wheels: 4 complaints (27% of all).
- Electrical system: 3 complaints (20% of all).
- Structure: 2 complaints (13% of all).
Symptoms owners describe
How many of the 15 NHTSA complaints mention each symptom (automatic count from complaint text; one complaint can mention several).
Components owners complain about
| Component | Owner complaints | involving a crash | Technical service bulletins (TSB) |
|---|---|---|---|
| Service brakes | 6 | 0 | 0 |
| Tires | 5 | 0 | 0 |
| Wheels | 4 | 0 | 0 |
| Electrical system | 3 | 0 | 0 |
| Structure | 2 | 0 | 0 |
What owners report
Short excerpts of NHTSA complaints in the original wording. These are owner statements not verified by NHTSA; personal data removed.
⢠The failed BCM can subsequently CATCH FIRE â potentially destroying the vehicle and endangering lives and property nearby. See photos attached from one SL owner's experience.
Complete brake failure while driving. No one was injured but the vehicle could not be stopped until the transmission went into limp mode with still no brakes. Now the ABS and SRS lights on. Brake pedal to the floor. I completely have new brakes speed sensors fluid exchanges and more.
If the car sits for 24 hours, it will not start. The electrical system is completely drained. There are many forms describing the same issue but yet the SL model is not included in a civil lawsuit. Mercedes-Benz definitely knows they have an issue in somehow it needs to be rectified.
[XXX] [XXX] [XXX] VIN # [XXX] SL550 2009 Since I bought this car 3 years ago the first day I am using it I got the problem say Reduced Braking Power, Depress Brake Pedal fully.
The door lock mechanism has failed such that the driver's door can not be opened from the interior which presents a serious safety issue. Despite being covered by an extended a mercedes cpo warranty mercedes refuses to cover the cost of the repair.
While trying to exit the vehicle, the door handle fractured and all of the doors automatically locked preventing the contact from exiting the vehicle. The vehicle was taken to a dealer. The technician diagnosed that the computer's theft system engaged once the door handle fractured and needed to be reprogrammed.
The contact stated that the brakes failed while traveling 35 mph and attempting to stop. The brake pedal was depressed into the floorboard. The vehicle was taken to the dealer and the contact was told that the hydraulic brake system failed and needed to be replaced.
Preparing to put a third set of tires on my mercedes benz sl550 @8500 miles. Already repaired 2 rims.?! No warranty. 3 tires have bubbles on them.
When owners complained
NHTSA complaints by filing year. The peak shows at what age the problems show up most.
Comparison
By complaint count this model year ranks 8,768 of 32,257 model years in the NHTSA data (top 27% most complained about).
On average one model year of the SL 550 has 5 complaints (13 years in the data). This year has 15, above average.
What to check before buying
- Service brakes. Pedal feel, ABS operation, leaks, discs and hoses.
- Tires. Tire age by DOT code, bulges, wear pattern.
- Wheels. Wheel runout, cracks, signs of a wheel strike.
- Electrical system. Scan all modules, test the battery and alternator, inspect connectors near the impact zone.
Other years of this model
Questions and answers
What are the most common problems with the 2009 Mercedes-Benz SL 550?
Owner complaints to NHTSA most often mention: service brakes, tires, wheels. Total complaints: 15. The most frequent symptoms in complaint texts: brake failure (20%), door locks, latches, handles (13%), airbag warning light (7%).
How many service bulletins (TSB) were issued for the 2009 Mercedes-Benz SL 550?
NHTSA lists 0 manufacturer service bulletins for this year. A bulletin tells dealers how to diagnose or fix a known issue; it is not a recall.
Should I buy a 2009 Mercedes-Benz SL 550 from a US auction?
Owner complaints describe defects, not crash damage. Before bidding, check the components listed above and review the lot photos: VinWind builds a report of visible and hidden damage by VIN.
Other 2009 models
Read also
Sources: public NHTSA data (USA): service bulletins and owner complaints; YouTube: links to videos credited to their authors. Complaints are owner statements not verified by NHTSA, and describe defects rather than crash damage. Data updated 2026-11-06.