Duh, accidentally posted this in the C6 section....more properly belongs here...

Coming back from a recent trip to Tahoe, my 2004 Z06 kept disengaging the cruise control. Did not appear to be related to going downhill. Sometimes I noticed the Traction Control Active note appearing in the DIC just before the cruise control disengaged. Cruise control speeds were in the 73 to 82 mph range; have not experienced this before.

Any advice, other than going to the dealer? (I don't trust dealers...)

Thanks in advance.

 

If Traction Control or Active Handling activate, Cruise Control is immediately disengaged so the the PCM can control the throttle based on input from the EBCM. Your Owner's Manual explains this in the section called "Cruise Control".

 

Thanks. I don't know why the traction control activated, though. I was just rolling along...no wildness going on when this occurred...

 

It sounds like you may have a problem with the active handling or traction control, look at this link and use it to see if your car has any AH/TC codes. you'll probably have several codes in several modules, don't worry too much about that, just write down your codes and then erase them all, then see what comes back.

https://www.corvetteforum.com/techti...D=26&TopicID=1

 

What size tires are you running front/rear ????

 

I have the original, stock tires on the car.

 

Are you certain ??? Classic symptom of a bad "tire stagger" on a Corvette is the Traction Control activating at 75 - 80 MPH .... post the sizes just to be sure.

Also, follow runamuk's advice and check for DTC codes. Go ahead and delete all codes, but before you do write them down (skip any that start with the letter "U") and list them in this thread.

Traction Control normally engages when it sees rear wheel speeds a certain amount faster than front wheel speeds. It uses wheel speed sensors at each wheel to make this determination. The EBCM (the computer that controls the braking system) constantly checks for "anomalies" that might indicate problems with the sensors. For example, if the EBCM sees one speed sensor consistently showing 60 MPH, while the other three agree on vehicle speed as it changes, the EBCM will post a DTC for that one wheel sensor. When it posts that kind of DTC you will get a SERVICE TRACTION CONTROL message on the DIC, and TC will be disabled (Warning light will turn on) for the remainder of that ignition cycle.

In your case, the EBCM believes the sensors are good, and is engaging TC because it sees a difference between front and rear wheel speeds greater than it is programmed to allow. Assuming the EBCM isn't "crazy", the obvious other answer is a tire size problem.

Only other possibility .... were you driving at night ... could it have been cold enough for ice on the overpasses ??? If you were on 80 it is possible that minor ice patches could cause TC to activate, especially up near Donner Pass. The TC system is pretty sensitive and it doesn't take a lot of wheel slip for it to kick in.

 

Thanks for the inputs. You guys are very helpful.

I'm heading to Baja at 0:dark:30 tomorrrow morning on a motorcycle trip, and I'll check all this when I get back next week. I know that the car has the original tires because I am the original owner. I have about 25,000 miles on them (I don't drive the Z-06 very much). Is it possible they could have worn enough in 25,000 miles to do this? I am pretty easy on the car; I've never lit up the tires.

As you have probably surmised, I am hesitant to go to the dealer with this problem, and I will do so only as a last resort. At the tender young age of 57, I have yet to have a positive dealer experience with any motor vehicle.

Thanks again.