StreetSpeed

Folks,

Cliff notes: Gutted the car over the winter, took the car for shake down cruise, spun the tires a wee bit and the service AH, Traction, and ABS light came on. Shut it down and started back up and everything was cool. What gives?


Ripped out the interior this winter and am headed to NJMP on Friday. I put in a new wheel, ripped almost everything out of the inside, and changed the shocks. I know any number of things COULD have happened while hack sawing away at the interior, but so far everything has run smoothly. I did pull a bunch of fuses but they were all interior lights, audio, and definitely NOT ones that had anything to do with the above issues. Car fires up normally, no codes or CELs, traction button works. I went for a spin, spun the tires a smidge, and then everything shut down. I checked it by slamming the brakes and locking them up. I gotta admit having no ABS was a little enlightening, but I'd definitely like to keep things running in check and turn them off when I want to. After I parked it I turned the car on, all the lights were gone, and everything operated normally. Unfortunately I didn't have time for another trip to recreate the issue.

I did change the shocks today and was careful (I thought) not to cut or disconnect any ABS sensors. If I did loosen an ABS wire, would it effect everything else as well? Seems to me it would light up as soon as I turned the car on if it did.

Last point is all my traction wiring is just flopping around in the cabin at the moment until I make some panels for the switches. I don't THINK anything would/could short out like this, but I'll attach a picture for comment.

Any help would be appreciated! The car is a new animal to me and I would prefer to turn traction off at my request and not at the cars'.

crease-guard

I have a C5 as well and gutted my car (way more than yours) to the point of taking out extra wiring. I would have this same issue for the first run or two and then reset the codes and all would be well. I would imagine you had the battery disconnected at some point? If you did, give it a few and go back and reset the codes. If stuff still isn't working, you're going to have to go back and retrace your steps to see if there is a connector or something loose.

I had a problem with trying to wire in a toggle switch to pop the hatch. Would work, then wouldn't, turned out to be a spotty connection in the harness plug into the BCM. It's gremlins like that you'll chase when gutting the car. BUT, once you get them sorted, the C5 is just a great track car platform.

Pull the codes the car is throwing, that will give us some idea of what's going on.

RX-Ben

check your error codes and then report back

StreetSpeed

I don't have any. I gotta put it on the trailer tomorrow morning - I'll hooligan about and see if it pops up again and leaves a code.

lefrog

Had issues with a low battery triggering that kind of crap. Once the battery was fully charged up again, no issues.

StreetSpeed

Good to know. My battery is definitely shot. I have to keep charging it just to get it to start. Hopefully when I put the braille in tomorrow I won't have any more issues.

froggy47

You really can't do much trouble shooting without a decent battery. These cars are uber sensitive to voltage.

mgarfias

Check battery, then grounds, then pop the EBCM connector - clean it out, and reseat it firmly. I'd also check the star connector thing by the BCM in the footwell, make sure thats all in good shape.

When it lights up and you lose everything, pull codes right then, see if you get a TCS - NO COMM

RX-Ben

Also check the wires coming from the wheel speed sensors (at the hubs) and disconnect, clean and reconnect them. Inspect for female connector pin spread before reconnecting. You can do a search in the tech section for some good posts on that.

fatbillybob

Gents,

Spinning tires does not cause this for me but rough off road excursions has done it 3 times. What happens and what do you do about this problem when it happens mid race? Last race I was forced 4 wheels off. It was rough and bumpy and caused the service active handling etc MIL to come on. The car at that point became undriveable. Sometimes brakes would be too sensitive and sometimes would not stop the car. The solution was to turn car off and turn it back on to reboot it. What can I do mid race? I don't feel good about turning the key off down the front straight at a high rate of speed then restarting the car. Not even sure that would work if that reset would work if the tires were moving.

RX-Ben

replace the OEM wheel sensor plugs with weatherpacks or deutsch weatherproof connectors. I have done this on two corners (using weatherpacks), working my way around the car as the OEM connectors fail. Also check the wires coming from the wheel speed sensors - more of an issue if you have 1 piece rotors, b/c of the heat transfer, but those wires can become abused (wrap in heat shielding for somewhat better protection, but cannot protect them from the heat from the bearing/hat). Any idea what codes were triggered?

mgarfias

Try rebooting the TCS while in motion? You can do the opts + fuel button four times thing while driving. get to the TCS section and hold down reset.

Not sure I'd want to try that while racing tho.

Scooter70

You don't have to turn the car off and restart it. Just turn the key to "start" while you're running down a straight. It won't engage the starter, just restart the computer.

rocsvette

Check/replace steering wheel position sensor, clean connection, that can trigger AH/TCS spurious signals.

RX-Ben

OP - did you check your codes on the DIC? You should get a historical code ("H" after it) for whatever caused the problem. Here is the procedure (obviously ignore if you have done this, but I've never had an ABS/TCS/AH issue without a code being thrown):
1) Turn on the ignition but don't start the engine.
2) Press the "reset" button to turn off any warning messages
3) Press and hold "options" and
4) While holding "options", press "fuel" four times within a 10-Second period.

StreetSpeed

5 codes for.tcs

C1221h
C1222h
C1226h
C1233h
C1248h

At NJMP and car was working and would light up after 5 or 6 laps, now the warning lights are on full time. I'll disconnect and reconnect some stuff and see if that wakes it up.

froggy47

Really? Never heard that one. Not sure I'd have the nerve.

Bill Dearborn

The early C5 EBCMs had some issues with unusual signals coming from the wheel speed sensors which were caused by driving on irregular surfaces. The ABS system would shut down and you were left with the base braking system. The problem usually occurred before the driver hit the brake so when the brake pedal was applied with the surety that ABS would keep a wheel from locking all of a sudden you had a tire going up in smoke.

12 years ago I was at a Touring Challenge for Corvettes event with Danny Kellermeyer and looking over one of his 99 Kit Cars. I asked him what the switch on the dash was and he responded that it was there to recycle the ABS while he was driving. He ran the B+ (12V) power to the EBCM through the switch and if the ABS quit he would reach over and toggle the switch which would cut and then apply power to the EBCM thus rebooting it.

Bill

StreetSpeed

I've been doing it all day! Works great!

I think I isolated the problem to the front right abs sensor. I cleaned it out, re-ziptied it in a better location, and it mostly eliminated the issue.

Bill Dearborn

C1248 is occurring because one of the other codes is active. Each of those codes indicate the subject wheel speed was zero for 60 seconds while the others were over 16 mph. Either you have a fault that skips from one sensor to another or there is a voltage/ground problem at the EBCM. Probably need to check G108 over by the battery to see if it is making good contact with the frame. If you can get a voltmeter on the power lead running into the EBCM when it is under load see if it reads 12V. Of course check all of the other possibilities such as battery cables, battery ground and battery positive cable connection to the electrical center.

Bill