mmehtas

My 2007 s550 has 60,000 miles and has not shown any issues with the transmission. The fluid was changed at 39,000 miles.

Today I was pulling into a parking spot and did not have enough room to make it. I put the car in reverse, but it would not move. I thought I had not pressed the parking brake while shifting gears, so I tried it again. The gear selector showed it was in "R", but the engine revved as if in idle. I then tried to move forward with no luck. I shut the car and restarted it, and the car behaved perfectly from then on. There was no shuddering, no vibrations, or anything else. It just acted as if it was in idle until I shut the car down and restarted.

Any thoughts? I have extended warranty that expires in 2 months. I am just afraid that the dealer won't find anything and then I will have major issues after the warranty expires.

ImInPA

It probably wouldn't hurt to take it in and have them at least check to see if a code was generated. You don't say if you have 4Matic or RWD. I have experienced, very rarely, a situation where when I come to a stop and quickly shift into reverse, it seems to take an inordinate amount of throttle to get the vehicle moving. I notice this especially if one of the wheels is on a slippery surface. I just figure it is normal for this transmission and its aggressively locking torque converter. Like yours, there is no vibration or anything else notably wrong. With only 2 months of warranty left, I would want to make sure it is not a valve body or something serious.

s5benzo

Sounds like the valve body is about to go ... I would definitely get that checked out and fixed before the warranty expires

mmehtas

Thanks for the replies.

It's a 4matic. Yes, I am definitely making an appointment. Even if the dealer finds nothing, it may help to have it on record in case the transmission fails after the warranty expires.

mmehtas

This story gets worse.

I made the appointment for this coming Saturday - this was the earliest they had a loaner.

Drove the car very briefly yesterday with no issue. Drove it for a doctors appointment this morning, just 5 miles down the road. No issues. From there drive down the highway about 15 miles. Upon taking the exit ramp, and stopped at a traffic signal, the car had very little power when I started to move. It did get up to 30 mph eventually, but felt like it needed a lot more pushing on the accelerator. Parked the car, and on my way back it drove fine until I got off the highway and it repeated the exact same behavior. A little later the "check engine" light came on and has since not gone off.

I called the dealer and I am now waiting for Mbrace to tow it to the dealership.

I will provide an update when I find out more.

s5benzo

Goodluck , let us know what they find

mmehtas

Thanks; I will.

The car was picked up by roadside last night and is at the dealer. Mbrace was a bit of a nightmare. Called them at 4.15, and got transferred to roadside. Told me I would get a call with a recorded message telling me when the tow would arrive, and that they strive to get to the customers within one hour.

Got the call at 4.30 telling me which towing company had been assigned and that pickup would be within 100 minutes. So far so good.

After the 100 minutes had elapsed, I called Mbrace again. Got put on hold while they got a hold of roadside and tried to find out where the tow was. Was told that the towing company had been called to a police emergency and they were delayed. They would come within 30 minutes.

After another 40 minutes, I called Mbrace again, and was on hold again while they investigated. In the meantime, I answered another call and this was a completely different towing company that told me they had just been contacted by roadside and he was on his way, but he was an hour away. Roadside came back on the line to tell me the same thing and could not explain why the original company had not showed. Eventually the car was picked up, about 3 hours after my first call. To their credit, everyone was very courteous and apologetic.

mmehtas

Here is the resolution.

I confirmed this morning with the SA at MB of South Charlotte that they had my car and that they were going to look at it. Got a call at 2 pm that the car was fixed. Just picked it up and it drives fine. Here is what the invoice says:

Malfunction of transmission speed sensor. Performed quick test found fault code 2767. Performed guided test process to replace valve body conductor plate. Performed R&R of transmission pan and removed valve body. Performed replacement of valve body conductor plate and assemble the valve body. Performed initial start up and fill procedure of new control unit.

The car runs fine but I am a little concerned that I may have issues after the warranty runs out in a couple of months. The resolution seems different than what others have reported - or it could be my lack of understanding.