HBC350

Ok, so I've posted about this before and now I'm looking harder for answers. My car, a 2009 C63 without PP, has an issue with the traction control system activating (with associated dead throttle) whenever I coast around a long sweeping turn such as a freeway offramp. Happens every time. I am running Yokohama AVID Envigors in the stock 18" sizes. Rears are brand new and fronts have about 40% tread remaining. Dealer claims issue is related to the difference in tire diameter between fronts and rears. WTF? The tires on this car don't wear evenly front to rear. I go through three sets of rears to one set of fronts. The tire diameters are rarely ever the same. Anyone else here experience anything similar? Basically, the dealer put a set of tires from a car on the sales lot on my car and said "see, it doesn't do it with these OEM tires."

CityOfAngels

How fast are you going through these turns?

HBC350

Coasting. 20-25 mph, not even close to traction loss, grandma-style. Light starts flashing, throttle goes dead.

jrcart

I believe this is a yaw sensor issue, that is activating your ESP, not really the traction control. The car is cutting the power becuase it thinks you are going to loop the car. It can happen at relatively low speeds on tight off camber turns.

Yuille36

Last week when we had rain here in Northern VA, I was accellerating out of an on ramp and my C63 car got a little squirrely with the traction control. And I wasn't accellerating hard, I guess the rear wheels were detecting slip, and activated. This doesn't happen in my E63. And I also noticed that the traction control light blinks on long sweeping corners, when I'm on hte accellerator. Again, this doesn't happen in the E63.

HBC350

Whatever it is, I don't think it should be happening under the conditions I am putting it to. I'd like to know what the computer thinks it is seeing that it needs to correct.

jrcart

A yaw sensor detects lean angles of the vehicle as well as gyroscopic movement (the azz end coming around on you). If you are in an off camber turn such as some off ramps it is very likely that the yaw sensor is kicking in. I have had the same thing happen to me on a few instances. THe speed you are traveling really has nothing to do with it kicking in. Push your ESP button once then go through the same turn and see what happens.

Dads C63

Is the traction control sensor light flashing when this happens? It could be something else. Are these left or right hand sweepers?

HBC350

Yellow triangle with an exclamation point in the center of the instrument panel flashes. Left and right turns. All speeds except snail.

Hans Delbruck

+1, you're off the throttle in a sweeper, the car might be anticipating the rear coming around and braking one of the rear wheels.

Like he said... put the traction control in Sport mode, it should be more lenient...