Pooh-cl

After the 2nd track event with my new to me 2002 C5Z06 I again received Service Traction Control Warning (maybe Service Active Handling warning - sorry its been a couple of days and not quite remembering).

DIC Codes
C1225 RF Excessive Wheel Speed Variation,
C1233 RF Wheel Speed Circuit Open or Shorted
and C1248 not on my code list but an internet search said it was -- DRP Disabled
ABS didn't work after this occurred (locked up brakes on turn 1 at VIR - oops)

Was driving in competitive mode when this happened.
Cleared codes and next run out drove with Active Handling OFF and same thing happened.

under 5k miles
car is under an extended warranty (fwiw); only used at the track
Stock passenger seat, race drivers seat.
Pilot SPort PS2 - 315 tires rear, 245 fronts

I did try to research this and basically just got confused. Do I start with looking at grounding issues? Yaw sensor problems? Could tire sizes be causing a problem? Any ideas where I should start with trying to solve this?
Thanks in advance for your help.

Jason

Check your bearings, which if always a good idea, then just clear it. Pretty sure everybody sees it. If your running with everything off it doesn't effect anything.

froggy47

I'd put a new RF sensor wire on, clear codes & drive it. Could also be the bearing.

Bill Dearborn

With a wheel sensor DTC you will have no ABS/AH/TC. C1248 is a result of the wheel bearing issue. DRP stands for Dynamic Rear Proportioning which means the EBCM proportions the amount of rear braking. The first thing to do is check the wiring to the wheel bearing. However, since you have an extended service plan find out if it covers replacing wheel bearings. Why pay to do it yourself when the plan will cover it?

Bill

geerookie

Also remember that there are two connections between the wheel sensor and the EBCM. Most people check the one at the bearing see no problem still get a code and replace the bearing. It works for awhile and then starts throwing codes again. Usually the problem is the connector on the engine cradle between the control arm mounts. This one sits horizontal gets tons of water, grit and grime and doesn't drain so it corrodes.

geerookie

Except ABS....without wheel speed at any wheel ABS is shut down.

crease-guard

Are you running stock size wheels?

I get those warnings all the time as well (although I haven't checked the second connections all that well, will do that next time I have the car on the lift). I run 18s all around and you cannot drive the car with the nannies on if you run 18s on all 4 corners, it will drive you nuts. I turn everything off and I'll get the service active handling when I get aggressive and loose in the corners. When I get back to the garage, turn the car off and let it cool down, upon starting up again the warnings are all gone.

Jay

longdaddy

another vote to check/clean connectors on both sides of the wire that goes into the bearing assy.

Jason

On my 2002 Service Active Handling doesn't affect ABS, I get it all the time and my ABS works fine.

travisnd

It depends on what the error is. My yaw sensor is bad so I get "SERVICE ACTIVE HANDLING" when I start the car, but I just hit reset, turn it all off and go about my way and ABS works fine.

However, if you have a bad wheel speed sensor it'll say "SERVICE ACTIVE HANDLING/SERVICE TRACTION CONTROL/SERVICE ABS" and none of it will work.

Jason

Most of us have sacrificed a set of tires learning that lesson.

sperkins

True. It's makes for an expensive day.

sothpaw2

I've had this same issue this year and last. It was caused by the wheel speed sensor wire right where it goes into the bearing. The wire was damaged because it was not properly supported when my mechanic installed the brake cooling ducts. Even with proper strain relief, the wire as designed was not intended to have any weight on it at all (there's a connector at the end of the wire...supporting even a portion of this mass during vibration is asking evidently too much for the wire). When I look at my rear wheel speed sensors, GM has a nice bracket there to ensure that the wire sees no force whatsoever.

So then--I would first check if you have aftermarket brake cooling or any mods in the area of the front brakes. If so, take a look at how the sensor wire is supported and compare to the rears.

The good news is I fixed this issue this year by just attaching the connectors to the brake cooling ducts so that the wires have no weight applied. It's an easy fix. The wire did not have to be replaced, it just needed for the car to stop vibrating it.

Good luck

Andy

CP Thunder

If you clear the codes, turn the key on but don't start the car, do the codes return immediately? If they do, it means the PCM can't see one (or more) of the hubs. At least this was my experience.

You can check each hub with a meter for resistance. I think 1050ohms (?) was the right reading but it was a long time ago but that was with SKF hubs. Regardless, its pretty easy to tell which hub is bad with the meter. If they all test good, start looking at the front harness., especially if you have headers, our harness melted on the left side down near the framerail.

Pooh-cl

Thank you everyone for your comments. Trying to process it all and will test some of the things you all mentioned. Here are some answers to your questions.

1. I am running stock wheels.
2. Service Traction Control and check engine came on and the codes listed even when Active Handling was turned off when driving on the track.
3. Extended warranty plan has whopping huge deductible so would rather not use it unless major problem that I can't handle.
4. When ABS didn't kick in was when I had the warning light on and didn't hit reset while driving (didn't realize that I should hit reset while driving). I'm 99% sure the code was only Service Active Handing not Service Active Handling/Traction Control/Service Abs.
5. No mods or after market brake cooling
6. Codes do not immediately return after clearing them. Only return once I start driving on the track (I drove home from VIR to NJ with no additional codes or warnigns).

A few more questions:
1. How do I check the bearings and or the wire to the wheel bearing (I do have the corvette service manuals and will check there though reading a list of instructions is NOT my strong suite. I glaze over after reading 3 instructions)?
2. What is the RF sensor wire and how easy to replace?

Thanks again for everyone comments and help!

96CollectorSport

The RF sensor wire is the wire that goes from the cradle to the wheel bearing on the right front wheel. There is a plug on the wheel bearing, the wire plugs into that and runs along the A-arm to the cradle where it plugs in. It's basically a short jumper harness. If I have a car come by the shop and it throws a wheel bearing code the first thing I do is check the codes - write them down. If it has a "wheel speed sensor open or shorted" code I will swap the sensor wires from side to side take the car for a ride and see if the code "jumped" from side to side - that will tell you if it's the bearing or the sensor wire.
I did have 1 car that it ended up being a ETBCM (ABS computer) but most of the time it will be either the wire or the bearing.

longdaddy

with a wheel off very easy to access as per instructions above. unplug both ends, check contacts (esp on the bearing side), maybe bend them a little to make tighter contact, spray with electronic parts cleaner etc

Pooh-cl

Thanks for the info. I will try that later today when I get back from some appointments since I need to remove/change the rotors anyway. I'll report back with what I find.