Hey everyone,
after 3 weeks of owning my first Vette, I am trying to diagnose a problem. I have some DTC (codes) from the DIC, but don't know if they are related to the problem.

Here it is. Sometimes while driving, the DIC will pop up the message "Active Handling" and at the same time, I will feel and hear the front right, or maybe it is both of the front wheel brakes pulsating quickly, like ABS does when it activates. The sound is a growling sound, like brakes slipping, grabbing, slipping, etc. The car will pull a little to the right, but never enough to make the car change directions.

When will this happen? Well, it can happen at any time. Usually, this has happened when making a sharp turn or hitting a medium bump/dip. Last time this happened, about 10 minutes ago, I was in a smooth, sweeping, right hand turn. On occation, it will happen when going in a straight line on smooth road. This has always happened in low performance situations on dry roads...no reason for AH to kick in.

So here are the codes:

U1016 Loss of communications with PCM (No SOH Message Received -RFA
U1064 Loss of communications with DCM (No SOH Message Received -RFA
U1096 Loss of communications with IPC (No SOH Message Received -RFA

What I am hoping is that these are an indicator that a simple connector is loose or something.

Can anyone offer a solid suggestion as to what is going wrong and if these codes are indicative of the car's behavior?

Thanks in advance for reading all this and offering your help,
Dale

1999 Mag Red Coupe MN6
AH, HUD, Z51

 

The three codes you posted here are meaningless. I, and many others, have had these for years and they are "history" codes relating the your Remote Function Actuators (RFA) that will sometimes set. AH or ABS actuation can sometimes occur due to a "washboard" or irregular road surface while steering or braking. Check for other codes. The ones here don't pertain.

HTH,
Robert

 

Thanks Robert,
Unfortunatel, the only other code is one for the LH seat vertical position sensor. I keep clearing these codes, but they come back next time I drive teh car. As for when the AH activates, it happens on smooth roads and at slow speeds. It is definately not behaving correctly. It still works when it is supposed to, but usually it is an unexpected surprise during very mild driving.

Thanks again,
Dale

 

since I put zo-6 swaybars on no more codes :rolleyes:

 

If this is happening while accelerating, then any bump big enough to allow one of the tires to spin faster or slower than the other, seems to set off active handling. Some cars are very senstive to small things like a difference of tread height on tires of the same brand, model and size. It could also be what you suggested, a loose connection on a sensor. I had ABS warnings occur at train tracks and large bumps even when I was not braking. Turned out to be a faulty sensor at the right front. So it could be a faulty AH sensor. I am sure other more knowledeable members can be of greater help.


[Modified by RunNE1, 7:36 PM 4/1/2004]

 

Run, don't walk, to get it fixed. An acquainance had the same thing happen, except that eventually her C5 did a right-hand turn on its own into a freeway wall on an onramp at 50mph, totalling the car.

 

I thank you all for your responses.
I cannot stress enough that while yes, I have seen small bumps, RR tracks, and other road imperfections cause momentary blips of the AH, the problem is that the AH will engage at times when the road surface is super smooth. I have quite an ability to notice details of how a car drives, handles, and how the car interacts with road surfaces. I guarantee that there is a problem/behavior that is independent of road surface.

My current belief is that the front right wheel sensor is flakey. It has ALWAYS felt like THAT wheel is the only one that reacts when AH is acting up.

Any more suggestions are welcome and greatly appreciated, as are all the ideas and comments already submitted.

Thanks,
Dale

 

i get those codes all the time on my 99. sounds like one or more of your shocks is bad if you can feel it while driving. consider replacing the shocks with 04 z06 shocks, and add the z06 sway abrs too. get it all from gmpartsdirect.com for just over $500 total. :)

 

Before replacing a bunch of parts, first put the car up in the air, pop all 4 tires off, then check each sensor and its connection closely. If you have compressed air, blow out the back of the hubs where the reluctor is, also try to blow out the sensors. Also check to see that the sensors arent loose and flopping around behind there. Sounds to me your system activation is too sensitive due to faulty input. The AH control module itself may be suspect. pitch and yaw sensitivity sounds like it is out the window. Try the simple stuff first.

Robert
http://www.gen3motorsports.com

 

Thanks guys,
What I have already tried is removeing the RF wheel and diconnectiong the wheel sensor, reconnecting, disconnecting, then reconnecting again. I figured it could be this connection, but that has not helped. I think the next step is to remove that sensor and see if I can clean it and test it. I have the GM service manuals and believe I can find a test procedure if I can get a little better at reading the darn manuals. Its there, but there is plenty to sift through to get what ya need.

Thanks again everyone, and keep them ideas coming.
-Dale

 

The codes listed have nothing to do with your AH problem.. They're normal codes seen while using the DIC to view them instead of a real scan tool.

Can't offer any help on your real problem though, other than to get some time in with a tec-2 to try and diagnose the fault.



[Modified by 99blackFRC, 12:41 AM 4/3/2004]

 

Hey Mitch, Im in austin too and my car has done the same thing for a year. I havent been able to spot it yet, but EVENTUALLY the car will throw ABS/AH codes. You just gotta be patient.

I'll look and see which they are, I keep losing the sheet of paper I have them written down on.

Anyway, just letting you know this is probably a common problem....I mean...2 in one city? lol.

 

Jim,
Good to hear from another Austinite. Why have you gone this long without getting it fixed? Does it feel like the same wheel is always the one being activated?

Thanks for your response, and if I get it figured out, I will let ya know what needs to be done.

Later,
Dale

 

I've waited this long just because im in the habit of turning everything off every time I get in the car anyway. The car doesnt try to kill you if you just shut off AH every time you get in.

Once I have money to throw at the issue, then I'll try to get it fixed, until them I'm fine with no AH....tons of corvettes dont have AH anyway, so its not a big deal to me.

BTW, the name is Jon, not Jim. Not sure why everybody calls me Jim.

Jon
http://www.ls1howto.com

 

Thanks Jon,
Sorry about the name mistake. I thought I took it from your screen name, but that was a mis-read on my part.

Take care,
Dale