C63Dave

Hello MBWorld,

I am new to posting on the forum but have enjoyed using this resource. There are so many great members and posts that I am grateful for. A couple months back I purchased a 2009 w204 c63 p30 package for a killer deal. Under 80,000 miles and the headbolts have been swapped already. I have been seriously enjoying my German muscle car's power, comfort, and the sound of course!

It has been a smooth 1,800 miles over the past couple months. I have added the ROW airbuses with the Age Pro Dry S+ filters. I did notice the car is "breathing" better and can run a little harder. I have also added the Suvneer "Godhand" CF lip to the car, and fairly happy with the fitment. Car was already lowered 2 inches so I gotta hit some driveways sideways, but I am used to it from my other vehicles.

The other day I was driving on a highway that climbs 3,000 feet elevation, a road I take 3-4 times a week. When I was driving the left side yellow warning triangle light flashed on and the car seemed to jerk and cut the engine power to half. It freaked me out because that was my first time experiencing something off with the car since my purchase. I backed off the throttle and continued to climb the hill. I descended and continued to watch for the light. It came on again when I accelerated, once again the light flashing for a moment and then turning off. I cruised the car home on the street and came home puzzled because I tried to recreate the circumstances again and could not replicate it. The next morning I got in and drove on the freeway and the issue happened again 3 times. Quick flashing of the warning light (I thought it was a CEL) and car lost most power and seemed kinda limp.

I searched high and low on these forums as to what the issue could be. It was hard because every time the light would just briefly flash on, then go away. I am also not familiar with the different warning lights on the MB dash. I am used to driving an old school Chevy that has no lights lol..... My research was leading me to believe that the O2 sensors may have been going bad....

I took my car into a highly rated shop (my first time taking it to a shop) and I was impressed when I arrived. There was an identical w204 c63 in the lot (mines was cleaner though) and another w204 AMG in the shop with the Weistec supercharger being installed. I knew I came to the right guys.....

The tech spent the afternoon looking over the vehicle and found the issue. It turns out the speed sensor cable in the right rear inner fender well had come loose and was actually hanging down on the tire. The vibration and friction was sending weird signals to the sensor and causing the ESP traction control to engage momentarily. I was very relieved when they told me this was the issue and that it could be fixed for $200 (probably could have done it myself). They ordered the part from MB and it should be done today.

I created this account and wrote this post because I was not able to find much information on my issue and figured someone else will likely experience what I have.

Cwagon

Thanks for posting your information.

Jbkidwell

Any other issues that may cause this? I'm having a very similar problem with my 2002 C240 not showing any codes and it only does this when the car is cold or at least within the the first few minutes of driving.

dattorob

After you confirm the battery is ok (check your voltage it plays a critical role in the ensuring your control modules work)
and tire pressures ok, try cleaning your speed sensor in your wheel with contact cleaner/compressed air , but also check the magnet is in place that's associated with wheel speed sensor.
I've also heard of a lock to lock steering reset but not sure that applies here.

ChrisHimself

i came here to literally say wheel speed sensor connection lol. I think someone replaced the wheel bearing (famous Wheel Works oversell) and they routed the cable poorly/didn't clip it in