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Anyone know which ground points service ABS / TCS ?

Jistari

Well-known member
Joined
Aug 30, 2006
Messages
254
Location
New York
Corvette
2001 Black on Black A4 Coupe
As many of you are aware some C5's experience intermittent DIC error codes due to inherently poorly designed grounding connections around the vehicle.
I am getting the dreaded "TCS C1214" (Sol Valve Relay Contact or Coil CKT Open) DIC code intermittently with the associated ABS, TCS disabled indicaters on the dash.
Although not a mechanic, I have done a fair amount of research on TCS related DIC codes and the conditions that cause them (bad grounds, water in pass footwell due to clogged AC drain, inferior parts in OEM EBCM) and have been down this road before (had my EBCM replaced last year), so this post isn't really about why I'm getting the current code (although I'm appreciative to anyone who can provide a definitive answer :) ), it's just a question I have not seen answered anywhere:
Thirteen ground points in C5 : G101, 102, 103, 104, 105, 106, 107, 201, 202, 301, 302, 401, 402

C5ZO6pictures012.jpg


C5ZO6pictures013.jpg


So . . My question:

Which of the thirteen grounding points on the C5 provide the ground for the components of the ABS and or TCS?


I'm assuming they might include 101, 102, 201 and 202 (that would be both the connectors (R+L) on the frame rails under the hood and both the connectors (R+L)by the rocker panels under the dash.
The reason I'm asking is to try and narrow down the spots to take apart and clean when this problem resurfaces during the life of the car.
Thank to Bill C for the diagrams from a previous post and much excellent info btw :w) and Thanks in advance to any respondents for your help.


Please excuse my posting this here, should have probably been in C5 Tech. Sorry about that, don't know how to delete it. Can a Mod move it foir me?
 
I have since found that the Grounds involved are G103 and G108 (Thanks Bill C )

The locations are as follows

The pictures in the manual do not help much. This is from the Master Electrical Component list in the manual.

G101 Forward lamp harness, on LH frame rail, near brake pressure modulator valve (BPMV) (CKT 150)
G102 Forward lamp harness, on the top of the RH frame rail, behind the RH headlamp assembly, ground for SP100 (CKT 250)
G103 Forward lamp harness, on LH frame rail, near brake pressure modulator valve (BPMV) (CKT 1250)
G104 Instrument panel harness, below the battery tray, on the RH frame rail, ground for SP208 (CKT 851)
G105 Engine harness, LH side bottom of engine, ground for SP122 (CKT 150)
G106 Engine harness, RH side of the engine, above the starter (CKT 451)
G107 Engine harness, LH side top, rear of engine (CKT 151)
G108 Forward lamp harness, below the battery tray on the frame rail (CKT 1251
 
Did you replace your EBCM with a Genuine GM Mogul?????;shrug
 
Ya know, I dont know.
It was just one of those things. The day I picked up the car from the place I bought it, the TCS error came up. The guy said they all throw codes if you let them sit in the showroom, and it would go away, or he would take care of it.
It did go away in a few miles so I let it go.

I started getting the code a few months later and had the car back to him a few times, each time it cleared up, but eventually came back and stayed.
It was almost a year when the problem just stayed (none of his fixes worked). So I brought it to a real vette guru who diagmosed exactly what was wrong. Turned out to be a bad ground on circut (556 I think) that killed the sensor on the EBCM.
Brought it back to where I bought it, showed the guy the diagnosis, and to his credit, he said I told ya Id take care of it, leave it (he fixed it no charge).
We discussed it briefly, but I felt funny about him fixing it after a year, so I didnt dwell on it, he said he replaced the ebcm, I thanked him and left.

It seems to be pretty much cleared up, I rarely get the error now (and this time, the one that I wrote this post about, has cleared itself up) seems to be related to low voltage. My oem delco went, so I replace it with a red top. I think the red tops die when they sit on the shelf. I brought the car back and had them test the battery and alternator, battery = good, but low charge, alternator fine.

I'm betting the error was voltage related, its been fine when I use the car for a while now.

When I get some time, I'll clean all the grounds.
 
Ya know, I dont know.
It was just one of those things. The day I picked up the car from the place I bought it, the TCS error came up. The guy said they all throw codes if you let them sit in the showroom, and it would go away, or he would take care of it.
It did go away in a few miles so I let it go.

I started getting the code a few months later and had the car back to him a few times, each time it cleared up, but eventually came back and stayed.
It was almost a year when the problem just stayed (none of his fixes worked). So I brought it to a real vette guru who diagmosed exactly what was wrong. Turned out to be a bad ground on circut (556 I think) that killed the sensor on the EBCM.
Brought it back to where I bought it, showed the guy the diagnosis, and to his credit, he said I told ya Id take care of it, leave it (he fixed it no charge).
We discussed it briefly, but I felt funny about him fixing it after a year, so I didnt dwell on it, he said he replaced the ebcm, I thanked him and left.

It seems to be pretty much cleared up, I rarely get the error now (and this time, the one that I wrote this post about, has cleared itself up) seems to be related to low voltage. My oem delco went, so I replace it with a red top. I think the red tops die when they sit on the shelf. I brought the car back and had them test the battery and alternator, battery = good, but low charge, alternator fine.

I'm betting the error was voltage related, its been fine when I use the car for a while now.

When I get some time, I'll clean all the grounds.
I just sent mine off 2 weeks ago!!!Mine just started acting up for a couple weeks and then the Lights came on for good!!!I went with the rebuild rout because there having some trouble!!!I sent it off to a guy in Missouri and he put a up grade in it and Guarantees it for as long as I own the car!!! I could actually see cold solder joints in the board with my naked eye!!! Fed Ex picked it up on a Wed. at 4:35 PM and UPS delivered it back on Fri at 10:35 AM!!! My Active Handling,ABS and Traction control work better than they ever did even when new!!!:upthumbs
 
When I was getting my service traction control soon I cleaned G101 and G102. They were both corroded with the green type oxidation. In the Bill Curlee thread he shows a few pics. of the corrosion. Sure as hell, the DIC messages went away.
 
When I was getting my service traction control soon I cleaned G101 and G102. They were both corroded with the green type oxidation. In the Bill Curlee thread he shows a few pics. of the corrosion. Sure as hell, the DIC messages went away.
Yeah well,after cleaning every ground in the car at least twice mine didn't!!! So I sent it off!!!:upthumbs
 
Yeah, I guess you have no choice then. Good luck with it, hopefully it won't take them too long. :)
They had it back to me in less than 39 hours,with a Long as I own the car Guarantee!!After driving it now I know it always did have a problem,it was not bad enough to trip the lights!!!:upthumbs
 
There is no substitute for high quality parts no matter where they are.
 
They had it back to me in less than 39 hours,with a Long as I own the car Guarantee!!After driving it now I know it always did have a problem,it was not bad enough to trip the lights!!!:upthumbs
That's awesome. Can't beat that guarantee too. :)
 
Yup, with the amount of reading I've done (and help from you guys) I'll keep it in line till it goes and stays gone, then I'll do the ABSFixer upgrade. Thats definitly the way to go (even better then replacing with oem parts).
 
Yup, with the amount of reading I've done (and help from you guys) I'll keep it in line till it goes and stays gone, then I'll do the ABSFixer upgrade. Thats definitly the way to go (even better then replacing with oem parts).
Brandon, AKA : www.ABSFixer.com is who did mine!!!Great guy,Willing to help you trouble shooting too!!!Fast Service!!!!:upthumbs:upthumbs
 
Please excuse my posting this here, should have probably been in C5 Tech. Sorry about that, don't know how to delete it. Can a Mod move it foir me?

I just saw this request. Sorry to be so slow.
Jim
 

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