2006 Mercedes-Benz CLS500 Problems

What owners report

Owners of the 2006 CLS500 write about two recurring themes more than anything else: brakes, specifically the Sensotronic Brake Control (SBC) system, and fuel odors traced to the tank, sending unit or pump under the rear seat. Brake complaints often involve a pedal going to the floor and a dashboard warning to stop, while fuel complaints cluster around the smell after filling the tank. Both tend to appear on cars with substantial mileage, though fuel odor reports also show up on lower-mileage examples.

1. 1
   Brakes

   Brake pedal sinks to floor / reduced braking (SBC)

   • 21 complaints (34%)
   • median 125,000 mi at 12.0 yrs old (18 state mileage)
   • 1 mention a crash, fire or injury
   • filed 2009–2024

   Complaints describe the brake pedal traveling all the way to the floor, sometimes with a dashboard message such as 'Reduced Braking Power' or 'Depress Brake Pedal, Stop Vehicle', and stopping distance increasing. Several owners say the condition appeared while driving at highway or suburban speeds, and some say the car returned to normal after a restart. Dealers and independent shops diagnosed the SBC hydraulic unit or pump as needing replacement; some owners were told the failure was outside a prior recall or warranty coverage, and others report the unit is no longer available. Mostly reported between roughly 60,000 and 170,000 miles, at varied road and highway speeds.

   3 related service bulletins

   What to check: Ask whether the SBC hydraulic unit has been replaced or serviced, and check the service records for brake warning messages. During a test drive, note any 'reduced braking' message and whether the pedal feels firm.

   2 excerpts from owner complaints in NHTSA records

   “I was exiting the highway when I began to push on the break pedal it went all the way the the floor. Good thing it was a little traffic because I was going about 40 MPH so I was able to turn off the highway in the grass and stop. But this is a major safety issue and this could have well ended bad for me. Without warning the brakes just stopped working and gave the error 'depress brake pedal stop vehicle”

   NHTSA complaint #11316895, filed 2020-03, 129,000 miles

   “I was driving and the reduce braking light came on. I pulled over stopped my vehicle because it stated that I needed to do so, restarted the vehicle and tried to make it home. I began to loose control of the steering and even though I was pushing the brake pedal to stop, the pedal went to the floor. I was in rush traffic and so scared that I would hurt someone or myself. I recently had my brakes and rotors replaced, months in advance. …”

   NHTSA complaint #11057260, filed 2017-12, 197,120 miles
2. 2
   Fuel system

   Fuel smell after filling the tank

   • 23 complaints (37%)
   • median 76,970 mi at 8.2 yrs old (18 state mileage)
   • filed 2011–2021

   Owners describe a strong raw gasoline smell inside the cabin or in a closed garage, usually after a fill-up, sometimes traced to the fuel tank, sending unit or pump area beneath the rear seat. Shops and dealers in the complaints often recommended replacing the fuel pump, sending unit, seals or the tank itself, and some owners say the odor returned after the first repair. A few mention a warranty extension on fuel tank components. Reported across a wide range of mileage, from under 30,000 to over 140,000 miles, most often right after refueling and noticeable when parked.

   5 related service bulletins

   What to check: Fill the tank during a test drive if possible, then check for a fuel smell inside and around the rear seat and in the garage after parking. Ask whether the tank, sending unit or pump has been replaced and whether any fuel-system warranty extension applies.

   2 excerpts from owner complaints in NHTSA records

   “After I fill the CLS500 mb tank with gas, and drive into the residential garage, an hour later the garage is filled with raw gas fumes. If I don't fill the tank completely, it seems to be okay. Sometimes the fumes enter the home, and my guests can smell them. It's quite embarrassing when you own a mb. The guests leave right away.”

   NHTSA complaint #10566955, filed 2014-03, 29,000 miles

   “After filling my car, I started smelling a gas odor coming from the driver side back seat area when I reach home about 2 miles away from the service station where I filled up. I figure the smell would have go away but everytime I drive my car I can be assured to smell that gas odor in the rear driver side passenger area which now is very annoying for a car I paid so much money for. ....”

   NHTSA complaint #10556905, filed 2013-12, 78,510 miles
3. 3
   Wheels

   Cracked wheels and tire damage

   • 6 complaints (10%)
   • median 64,000 mi at 6.5 yrs old (5 state mileage, few)
   • filed 2007–2019

   Complaints describe cracked rims and tires blowing out or splitting, sometimes on the highway and sometimes at low speed over potholes. Owners say they replaced rims and tires and that the problem recurred, and some report a loss of control or a strong pull in the rain. Dealers in these accounts generally did not provide a diagnosis or repair. Reported from under 30,000 up to about 140,000 miles, often described as occurring on rough roads or over potholes.

   1 related service bulletin

   What to check: Inspect each wheel for cracks and bends, especially on the inner lip, and check tire manufacture dates and sidewall condition. Ask whether wheels or tires have been replaced and whether the car is driven on poor roads.

   2 excerpts from owner complaints in NHTSA records

   “Based on my personal experience and those of other mercedes owners of the same vehicle that I have spoken to over the years as well as mercedes service department employees , I know that this car has a long history of blowing tires, damaging rims in low speed pot hole incidences . The rims crack and the tires blow . This is dangerous and very expensive to repair or replace.”

   NHTSA complaint #10610236, filed 2014-07, 29,000 miles

   “While driving on the freeway at 65mph, I heard a loud thump. Immediately exited on the nearest off ramp, thinking that I had a flat tire. I checked and could not see a visible hole in the tire. When the tire was removed, the shop indicated that there was a huge rip on the inside of the rim. Me being confused, I advised him that I did not hit a pot hole, the technician indicated that he can tell the was the metal was ripped, and the tire was not punctured. …”

   NHTSA complaint #10456902, filed 2012-04, 64,000 miles

Buying note. Have a pre-purchase inspection focus on the SBC brake system, the fuel tank and sending unit, and the wheels, and ask for service records showing whether the relevant repairs or updates were done. Mileage alone is not a reliable guide here, since fuel odor and wheel reports appear on lower-mileage cars as well as high-mileage ones.

Summary written with AI from a sample of 57 NHTSA complaints for this model year (picked at random, with complaints that state a mileage and recent ones taken first), then checked automatically against the source records. Where a problem shows a complaint count, every complaint for this model year was matched with fixed keyword rules (written with AI and tested against the sample), and the mileage, age and repair figures are calculated from those complaints; owners' figures are as stated, not verified. Other counts refer to the sample. The excerpts come from NHTSA's public complaint records and are unverified; capitalisation is normalised, NHTSA staff notes are removed, and shortened text ends with “…”. Something wrong? Request a correction.