Dustindustrial

About 8 months ago now I picked up a pre-owned 2009 C300 Sport 4MATIC. Overall, I've been really happy with the car, and up until recently it's been problem free.

A few days ago I backed up out of a parking spot, shifted into Drive, hit the gas, and nothing happened. The car didn't move, the engine didn't rev. I shifted into Neutral briefly then back to Drive, and everything was fine. I hoped it was just a fluke thing.

The same thing happened again this evening after backing up out of a parking spot. This time shifting into Neutral then back to Drive made no difference. I also noticed that the yellow exclamation point above the instrument cluster lit up. I ended up having to put the car in Park and shut it off. I started it back up again, and everything was fine. One other thing I've noticed is that both times this has happened, I've been unable to fully depress the brake pedal. It moves down slightly, then stops. I have noticed no other issues with the car. It seems fine.

I'll be calling my indy tomorrow morning to make an appt., but was hoping maybe someone could give me some idea of what might be wrong. I'm really hoping I'm not in for a costly repair, right after Christmas shopping.

Plutoe

no doubt your indy knows the MB transmission and has the test equipment--maybe he will look at the shifter selector switch ,however with out DAS Xentry-------

Dustindustrial

Yeah, these guys know Mercedes. Years ago I had an ML320 with clogged heads. I used the local Mercedes dealership for maintenance at that time, and after 3 weeks of back and forth, with them telling me it was fixed, and then the CEL coming back on, I tried these guys. Thirty minutes and $75 later it was fixed. I've stuck with them ever since.

They offered to squeeze me in today, so I dropped the car there this morning. I should have at least a diagnosis today, and will post back when I know what's going on.

Dustindustrial

Just heard back... They can't find anything wrong with the car, and said unfortunately, they need to refer me to the dealership.

michail71

Very weird problem. So the car didn't even want to roll?

I wonder if it's something to do with the braking system. Some cars cut the throttle if it thinks the brakes are engaged. I wish it did this with the parking brake. I've already backed out a couple times with it on. It only wars when in forward drive.

Was that the traction control light that you saw?

Dustindustrial

Sorry for the delayed reply. I got busy with the holiday. Yes, the car didn't move at all both times this happened. It hasn't happened again since, and everything else with the car has been fine. I dropped it off at the dealership first thing yesterday morning. As of the end of the day yesterday, they found absolutely nothing wrong. They were going to drive it for a bit today and look into it a little further, but I have a feeling I will just have to pick it up, and wait and see if it happens again.