Battery was 12.24v yesterday with key off. I don’t have it on a trickle as it’s getting driven some right now. I have a feeling that it’s this battery, as I’ve never bought anything from AZ that was electrical and was actually any good. Prolly should throw a battery at it. Would a low voltage situation such as this cause the no-comm issue?

 

I do have a nice battery charger btw…

 

Yes, a weak battery may cause a no comm !!…the battery may be good enough to start the car but not enough to power some low current draw circuits…if you buy a new battery get one with a high RC like 120 or 140 minutes…RC is more important than CCA… the AC Delco Professional Silver High Reserve is a good battery. It’s also a good idea to do a voltage drop check on the positive and negative side of the charging circuit with a load on the electrical system…you don’t want to drop a lot of voltage (.5 volt but closer to .2 is better) across either side…if you need help on how to do this let me know…if you replace the battery and you still have a no comm can be that EBCM being faulty !!

 

Going to try a battery. I’ll report back. Appreciate the help!

 

Id tend to agree here, but it’s worth a try. Both of my other C5’s never got drove. I put 2500 miles on the 2000 and I put 2800 miles on the 02 Z, with batteries always almost dead to completely dead and I never had a code on either of those cars. It seems to me, the more I read about the electronics of these cars, age adds to the issues here. This 03 Z has just turned 23k miles, is darn near a perfect car, yet has this nagging issue. ABS module has just got back from ABSFixer, so I’m fairly certain it’s not the issue. I hate electrical gremlins like this. I’m a Mod over on LS1Tech and can handle anything internal engine. Been in high end engine stuff since the early 90’s. To make matters worse, I’m an electrician by trade, but electronics is way different. I understand the theory, but not my wheelhouse.

 

Update. I talked with Brandon at ABSFixer and I’m sending him the original ABS module that was sent to Delphi 13 years ago and claimed it couldn’t be repaired. Brandon thinks he can fix it. We believe there’s an issue with my current ABS module, which is not original to the car…prolly only non-original part on the car…which is causing my problems. The current module was sent to someone else besides ABSFixer, and had a hack-job with a soldering iron inside of it. I’ll update next week when I get the module back. I load tested the battery in the car and it is fine. It has a 120 reserve capacity and just needed a little charging. Keeping my fingers crossed over here.

 

Update…so the original module is on its way back to me and it’s unrepairable. The module in the car currently has already been to ABSFixer for repair and was found to have been repaired previously. Brandon found a lot of solder on the daughter board, and cleaned it up, bench tested it, road tested it, and found it to be ok. Contacting him about this issue he told me due to previous repairs made by others, he didn’t trust the module. So…I’m looking for another module at this point. In other news, car has been driven to school every day for last week and it’s awesome, minus the stupid light on the dash. I’m driving it tomorrow 50 miles for new tires. Pretty sure I’m buying one of the last sets of Michelin’s available for Z06 fitment.
I’ll update this thread as needed.

 

Update…module located and installed. No-comm code is gone but now have the C1242 code. I’m bench testing the abs motor and will update. In the car it won’t do anything (buzz or run or anything) with 12v straight to the motor. I think I have a froze motor? I’ll update thread with findings. Brakes needed bled anyway…glass half full approach.

 

That didn’t take long. I used an 18v battery and straight wired the motor. The motor turns very freely, and I let it run for 30-45 seconds. That’s good news. I’m letting the brake fluid gravity drain tonight on my lift at each caliper into buckets. I’ll flush the system tomorrow evening and then re-fill and bleed the brakes. From there I’ll continue to troubleshoot the electronics. I refuse to let things beat me and this is no exception. Done for the night…World Series game 2 is starting.

 

You’re everywhere man!

Do you have a fancy scan to to run the abs system while bleeding the brakes? Or do you just run the ABS motor manually?

I let my 2000 dribble drain like that and had to have a shop do the bleed job using a Snapon scan tool.

I had just bought the car and didn’t know diddly about bleeding an abs car.

Everything works on my 2000, it’s a miracle!

Ron

 

Ron!! Yeah I’m on quite a few sites. So I’ve got this straightened out today. No scan tool needed. I let the car gravity drain for two days. Prolly only took a few hours, but I didn’t get back out to the shop for 2 days. It bled easily. I went the RR-LF…LR-RF method. Brake circuits are criss crossed on these cars on purpose. Went through the 4 calipers 4 times with my Mighty-Vac. Had to top-off the reservoir 4 times, but got clean fluid at each caliper. No bubbles, hard pedal. Old fluid was dark…reservoir had soil deposits in it and had to be removed and scrubbed.
So I got the bleeding done, and put the connectors back on the ABS module up front. Got in the car and turned key to on position. Toggled through and deleted all previous codes. Said a prayer, and started car…ABS light was off, but traction Control light was still on. Turned car off. Toggled back through codes and deleted TCS code 1242 again. Restarted car and it’s gone. Held down Active Handling button until Competitive Driving mode appeared on display. Turned that off and on a few times, and it’s good. What a relief. At the end of the day, I think putting an 18v Ridgid battery with jumpers to the ABS motor and running it a while fixed the 1242 code. That and maybe the new brake fluid in the system freed the motor up to where it turns easily when commanded. I don’t know…I’m an engine guy, but I get joy from beating issues like this. Hopefully someone out there gets some help from this thread. Bleeding clutch is next and at that point I’ve changed all the fluids…coolant, oil (twice), rear end dope, tranny fluid, brake fluid now…I even changed the washer fluid. This car sat for years…

 

words such as ASSume and Fluke are dead giveaways you're an electrician. Good luck! Sorry I can't help.

 

Yessir, I co-own an electrical contracting company. Car has been trouble free since this post back in October, so all is good. Appreciate the bump.

 

Nice work. I have a 2000, like Ron, and mine is another miracle, in that it still works, too!🤞🤞 Where in the HELL is the wood to knock on????!!