I was driving on the freeway and noticed that my car would not accelerate and rev high in RPM. I have to pull over on the shoulder of the freeway since I am losing control of the car. I was about to call the tow service but I recover after I restarted the engine. At the dealership, the dealer has determined to a sensor on the transmission but said since my warranty expired, I have to pay $1300 to get the sensor replaced. This is terrible since my car has only 45000 miles on it. In addition, this is a common issue based on the forum discussion and Mercedes should have a recall on this issue. This is a terrible customer experience and I don't know how I can trust them.

- Cupertino, CA, USA

I was on the highway and the car suddenly stopped accelerating and the RPM's ran way up and the car would not accelerate. I tried putting it in neutral then drive and nothing. I pulled over turned the car off for a few min. Then back on. The car operated normally. The check engine light also came on and I had all the necessary service done on the car at that time. The car has done this increasingly for the last year and it is now becoming a hazard. The car has started jumping when put in drive and it is alarming. I cannot afford to replace the transmission and I feel Mercedes should take responsibility for a defect in this model. I have children and this is my only car. I don't feel safe in it anymore and my children don't either.

- Hoover, AL, USA

It occurred on the freeway in stop-and-go traffic. The vehicle would not accelerate and the RPM ran high. The transmission gear indicator went blank. I had to pull over, turn the car off, let it sit, then when I restarted the vehicle, it was normal again. I had only 38,400 miles on the vehicle at the time of the failure! online there are many complaints regarding the 2006 2007 C230's with the same problem. An independent repair shop said it is perhaps the transmission speed sensor which is part of the electrical conductor plate assembly. When talking to the dealership about my vehicles camshaft sensor failure repair and possible balance shaft issues, 7 months prior to this incident, the service rep admitted that they have many repairs with transmission control problems and encouraged me to buy an extended warranty! here is a quote from an independent repair shop: "these units are failing so often that the dealer has restricted selling them even in their own shop. To order a part, the dealer must submit a request with computer scans and control unit log reports of the suspected failed vehicle's electronics. The factory then sends the parts they deem necessary for the repair (conductor plate assembly, or complete valve body)." There is clearly a defect going on and I too would like a recall investigation through the NHTSA. The repair on this is thousands of dollars!

- Portland, OR, USA

The contact owns a 2007 Mercedes C230. The contact stated that while exiting the highway, the vehicle engaged from park to neutral independently and decelerated. The contact stated that the vehicle had to be turned off in order to correct the problem. The contact took the vehicle to a mechanic and was told that the failure could have been a problem with the transmission internal speed sensor or the shaft balancer. The failure mileage was 71,321 but updated 9/10/12

- Regall Park, NY, USA

I have a C230 sports sedan with 45,000 miles. The transmission had been sticking in gear, but if I turned the car off and removed the key it would reset and usually be ok for a while. Now it is stuck in first gear, and nothing I have tried has done any good. It will not shift out of first gear. It has an automatic manual transmission but the manual function does not work and even trying to shift manually does no good. This is a common problem with this model and yet mb has never issued a recall. This is pretty clearly a factory defect and needs to be addressed.

- Mountain Brook, AL, USA

Car seems to stay in one gear and does not downshift or upshift when needed. The only solution is to stop car, turn off and restart. It is a risk to enter a main road because of not knowing what gear the auto trans is locked or if it will shift to another gear to get up to speed. Dealer checked car once and said they could not find anything wrong but it seems it is a known issue the transmission problem for these model year.

- Mason, OH, USA

Vehicle seems to run fine but after a cold morning start the check engine light illuminated. After taking it to the dealership for diagnostics (totaling $105) it was revealed that the code rendering the balance shaft or possible bad sensor was the reason for the check engine light illuminating. The estimate cost for this repair is ranging from 5 to 6 grand. This is highly unacceptable for a vehicle with only 45,000 miles. 2007, Mercedes Benz, C230, black on black, that has been stored for a majority of its existence because I am deployed overseas does not send a good impression when the company will not admit that there is a definite problem with this engine type. In today's economy, consumers spend a little more to reassure this type of repair is avoided by purchasing a more reliable source of transportation. I guess I should have purchased a Chevy or Ford, at least then I would be expecting this type of nonsense.

- Houston, TX, USA

Vehicle would not shift out of first gear. Rpms were at shift level, then engine shut down. Restarted and revved engine, loud wailing sound. Car was towed to Mercedes Benz, they said transmission pump bad as well as transmission, needs replacing.

- Indio, CA, USA

The engine light came on asking me to go to the next gas station and check oil. When I took to the next day to a mechanic and upon a thorough diagnostics, I was told that the balance shaft (in take camshaft code 1208) and exhaust camshaft, code 1200 need to be replaced due to premature wear and faulty parts.

- Clifton, VA, USA

My 2007 C230 automatic sport sedan that I purchased pre-owned and certified from an authorized mb dealer in 2009 has been experiencing problems since purchase. I have experienced extreme loss of acceleration and running at a high RPM. It first occurred a few weeks after I purchased the vehicle. I was entering a parking garage with a steep hill and as I drove up hill, the car struggled to accelerate while the rmp ran high. I feared the vehicle was about to roll backward and I quickly applied the brakes, placed the car in park with my foot still on the brake. I turned it off and restarted and was able to continue into the garage. I took the car to mb service and after they tried to say it was nothing without reviewing the vehicle, they finally agreed to do a diagnosis. I was advised they found a faulty sensor and it was repaired. Several weeks later, it happened again while in the parking lot of my residential building as I attempted to back into my parking space. The vehicle did not accelerate and the rmp ran high. Turning it and restarting again remedied the problem. The third and forth time it occurred on the high way during my normal commute to and from work. The issue re-appeared in busy traffic. The vehicle would not accelerate and the RPM ran high. Each time it has occurred, I have had to pull over, turn the car off, let it sit, then when I restarted the vehicle, it was fine and I drove off without any problem. I have done some research on line and have found that there are numerous complaints regarding the 2006 2007 C230's with the same or similar problem described and it appears to be with the transmission. There is clearly a defect going on and I would like to request a recall investigation through the NHTSA. Updated 11/01/11

- Chicago, IL, USA