Ostendadler

Hi guys,

I've been driving the Z a lot these last few days and I've finally managed to replicate the issue.

Whenever I drive the car over 50mph-ish (on public roads) and have some turns or bends to the right I can hear some light rubbing coming from the left front wheel with a. If its a long bend the active handling will then start kicking in making the experience mildly annoying as I can feel a slight resistance in the steering. This doesn't happen at low speed or coming out of my multi story parking at all.

If I try and take a corner in a spirited fashion to see what would happen (which I tried in the name of science) and it was absolutely horrendous. The car seemed to emergency break on and off a quarter of a second two or three times during the turn kicking me back and forth slightly.

I would bet on a bearing being on its way out but I can't really fathom why the active handling would kick in on light turns. This has been happening more and more and very very quickly.

The car has 23.000 miles (2k mine) and I drove it spiritedly a few times but aside from that its been a few cars and coffee run and no track duty (yet).

This has shaken my confidence a lot and before I take it in to get the speedometer tuning done I wanted to hear what could be the outcome since so many issues are listed here. My research here have come up with a potential bearing issue. What do you think?

I'm on a very unlucky roll.

As usual your help is appreciated.

Eddie

PS: I daily drive a base c6 and have never faced such issues on the same roads.

PS2: My SERVICE ACTIVE HANDLING SHOW UP ON DIC AFTER DRIVING BUT GOES AWAY IF I STOP THE CAR

Dan_the_C5_Man

Really sounds like you have two different issues going on.

Active handling issues indicate a problem with the wheel hub speed sensor.

The noise you describe might be a bad wheel bearing.

But to the point, if you do have a bad wheel bearing, when you replace that you'll also get a new wheel hub speed sensor.

So in this case you might get a 2 for 1.

Ostendadler

Dan you're the man!

So a quick research comes up with this:

http://www.cultragfactoryparts.com/c...&position=left

Am I in the money ?

psp6158

And don't forget about the steering wheel sensor in the telescopic steering wheel. Just a recent thread where it was explained in detail. It was actually causing wheels to lock up. I would rule out Dan's theory first... Keep us updated

Ostendadler

I did glance at that post but I was under the impression that the wheel sensor issue was more general in the car's bad habit.

In my case it is so specific (only right turn) I was wondering what else it could be.

Ostendadler

Well its going in the shop tomorrow for some inspection to see what it is. Will keep you posted

Bill Dearborn

What year is the car? 06-08 cars had issues with the steering sensor connector and GM installed a comb to keep the connector properly seated so there wouldn't be any spalling of the metal pins in the connector.

Intermittent signals coming from that sensor would cause unintended AH activations since the steering sensor along with the lateral G and yaw sensors are the parts of the system the EBCM looks at to determine whether or not to activate AH.

The wheel hub contains the wheel speed sensor and if the hub is loose you will get a failure of the ABS, Traction Control and Active Handling and will see messages on the DIC for all three.

However, the wheel hub doesn't generate a signal that activates AH it only generates a signal that feeds back to the EBCM what is happening at each wheel after AH activates. The steering sensor is only used by AH and that is why issues with it only display AH messages.

If your car is an 06-08 you can remove the driver's side lower dash panel close out and crawl under the driver's side dash board and look up at the sensor where it is mounted to the steering column. The connector is readily seen from that vantage point and you can tell if there is a pink plastic fork stuck in the connector. If not you need to get one.

In 09-13 cars GM used a different brand and design steering sensor with a different connector and the problem didn't exist with those cars. However, that still doesn't mean the sensor itself isn't giving spurious signals that might cause activation AH.

You can check your wheel hub to see if it is loose and requires replacing just by jacking the proper corner of the car and placing your hands on top and bottom of the wheel and rocking it up and down. If it moves too much the hub has to be replaced.

Since all of this stuff is electronic and depends on a proper battery voltage supply make sure the battery is fully charged and in good condition as a low or bad battery can affect electronic performance.

The message about service active handling is generated when an ABS failure code related to the AH function is present. However, all of that resets when you restart the engine so if you want to read the associated codes you have to plug in a scanner capable of reading ABS codes while the engine is still running.

Bill

Ostendadler

Hey Bill,

Thanks for the input. The car is an early 11.

the assembly hub/bearing on the left car seems to be on their way out so that's going off. i also noticed the front bearings, upper arm bushings and front brake duct need some love too.

Promise I won't leave that post un-answered.

Well that will keep me busy during the summer here.

Best,

Eddie

Ostendadler

Hello guys,

it took me a while to find the time/money to ship the parts. But i'm on the case now:


I did the wheel bearing and speed hub test by rocking all four wheels and the 2 front ones failed the test. I replaced all 2 of them.

My Ball joints also looked dated and got replaced with some heavy duty after market parts. The Bushings also got changed because they didn't look good. The battery is brand new and trickled charged. The car went through a full re-alignment for all 4 wheels. The car came with ZR1 brakes in the front and Z06 brakes in the back.

After all this i'm afraid nothing solved my problem I still get the damn active handling over reacting on my left wheel when turning right.

I did however get a "SERVICE TIRE MONITOR" from my front left wheel sensor and the "SERVICE ACTIVE HANDLING" appeared as well but vanished the following day. My pressure is xxx in the tire and I checked its level. Driving modes seem to be offline as I can only turn off traction control on or off. ( i have dual ride mode).

Could the faulty tire sensor be the culprit of all of this? Is this it? http://www.zip-corvette.com/10-13-wh...-domestic.html

Should I just give up and accept my fate and get shaved by the dealer here?

MTPZ06

Say what? You have CCB's on the front and steel rotors on the rear?

Dan_the_C5_Man

Not really anything wrong wrong this combo, if you were on a budget, that's how you'd get superior braking (fronts do 80 percent of the work in hard stops).

Dan_the_C5_Man

Yes!! A non-working TPMS sensor will cause the brakes to be applied mid corner at over 55 MPH.

They seem to particularly problematic on this platform, I don't recall having issues with flaky sensors on the C5.

Anyway, either replace and / or retrain the TPMS sensor(s) or buy a box to eliminate them.

Ostendadler

It came in that format when i bought it in a sad state from the gentleman who brought it from texas.

i intended to change that but first things first.

Thanks for clarifying the point on that faulty tpms. Hopefully this should solve this issue.

Ostendadler

weird indeed. I have one faulty sensor for the past 3 years on my 06 c6 base coupe and never had any problem. Don't understand what is the problem for the z. Thank you so much for thr heads up.

i will update this thread once it is done.

also dan is this why i only have tc on/off so far no other options when pressing the tc button ?

Dan_the_C5_Man

What year is this car? I've heard from others that state the earlier model years were more "forgiving" than later years when it comes to faulty TPMS. And depending on what you are looking for (even if you have a later model year that doesn't mean you have PTM - my 2011 does not), it may be normal or it could be a symptom of the sensor issues.

Ostendadler

The car is a Feb 2011 produced model so i got the magnetic ride control but if my memory is correct the PTM only got introduced later on.

Dan_the_C5_Man

You are correct. If everything is working properly, you should have the ability to cycle through the standard modes, and of course holding the TCS button down to shut everything off.

Messing with the BCM programming (where the AH / TCS features live) is not common at all, so I wouldn't expect that to be the case.

Maybe create and post a quick YouTube video of the dash so we can see what's happening.

Ostendadler

I ended up having not one but two sensors busted. So sadly i got to head back one more time after the second sensor has been fixed to reset the system. I can almost see the light at the end of the tunnel. Will keep you in the loop.

on a seperate notr they are unveilling the c7 zr1 here this week. A perk of living in supercar city!

Dan_the_C5_Man

I heard about that, very cool, altough I am wondering if they couldn't keep 650 HP cool, how will that work with 750?

Mordeth

4 more heat exchangers, a larger blower that won't overwork/overspin itself, a larger hood, larger intercooler bricks and opened up the front grille for significantly more cooling and airflow. Other changes as well. It shouldn't overheat the way C7Z does on a road course. I've got a deposit down on C7 ZR1 and currently own C6Z and C7Z.