csc67

Ron,

First of all, thanks for the time and effort you are putting toward this resolving this issue

Do you happen to have an update?

Has anyone contacted Steve Stringfellow lately to see if he is interested in providing assistance?

Bill Curlee

I'm glad to see that this post is still up and running.

If anyone has a defective 97-2000 EBTCM, maybe we can try to figure out whats wrong with it. The more we play with these units, the more we learn and maybe we can come up with common failures and fixes.

If the microprocessor is defective, STICK A FORK IN IT,,,, ITS DONE! BUT,,If the problem is a common component on the main board or a solder issue,, those issues are easily resolved.

Mike

Im aware that they wave solder the boards. They still do a lousy job!

Bill

madmatt9471

Bill I do have an extra Unit that is defective - I will have to dig it out.

I will be gone tomorrow but will be around this weekend. Here is my email - madmatt9471@sbcglobal.net

I just need to know where to send it to you!

Thanks,Matt

RonSSNova

Hey boys,

Unfortunately my FA gal never tried to dissolve the goo. She pretty much figured that anything that would do so woulr ruin the already dead circuitry.
I should get it back from her I guess.
And be happy mine is working fine!

Ron

FL_Dave

I'm not so sure that a failed microcontroller would be an impossible fix. Usually these things are a standard device (eg 80c196) with propriety microcode. Given the low volumes for this vehicle, that chip is probably not full custom. If so, one might be able to program another CPU then surface mount it into the old board. This type of soldering isn't something most of us do in our spare time but computer manufacturers do it every day. (Humbly contributed .... as I have a great deal of respect for Mr Curlee and all the help he has provided to us Vette owners.)

Dave

Bill Curlee

]

Dave

NOTHING is impossible to fix,, but sometimes its way beyond what the ordinary person has access to. I watched a RE BALL Solder a Processor in a computer on U tube. That was pretty cool and he also fixed a cold solder joint on a PC Main board in his oven.

How would you get the EBTCM program out of the processor and into another one?

Is there an easy way of gold disking a processor?

If you have that much experience with electronics and access to all the specialized equipment, you should look into repairing C5 Instrument Panel Clusters (IPC) You could make a fortune!

Bill

FL_Dave

Hi Bill,
I’m not advocating that ABS CPU fix is for everyone, I’m just saying let’s get the coating off the board and see what we’re looking at. We have an amazing wealth of knowledge in the group and many seem motivated to continue enjoying their C5’s w/o those pesky warning messages. I can contribute some knowledge but need help from others. Together, maybe we’ll come up with something.

I don’t know what cpu is on the ABS printed circuit board but I do know that Intel and Motorola and microcontrollers were popular around that time. Also, unlike personal computers and cell phone manufacturers, General Motors had a long design cycle and long life for their products (a few years for the former vs. a decade or more for automotive manufacturers).

The annual volumes for C5s were 20ku - 30ku or so and the ABS module isn’t commonly available - suggesting the design was somewhat unique to that generation of cars. Those volumes aren’t large enough to justify a custom CPU. So it seems likely they used a programmable microcontroller and added their own proprietary code.

I don’t know when the C5 ABS was designed, but let’s say it was around 1995. One popular and inexpensive microcontroller that was commonly used at that time for these kinds of applications was the 80c196 in the 68 pin PLCC package. If it is a microcontroller in a PLCC package GM may have either used a socket or soldered the chip in place. If they used a socket, then R&R of the chip is pretty easy. If the PLCC is soldered, many “rework” technicians are quite skilled at removing and replacing those chips (search “drag soldering PLCC” on youtube). Given the solder quality of other electronics in the C5, it’s a reasonable bet that a quick drag solder would fix some of the CPU issues. But let’s say soldering doesn’t work.

What about the microcode? I doubt GM would hand over the code, but it’s possible. If they don’t, I’m a little rusty on programming microcontrollers. For example, I can’t remember if you can simply put a working uC in one side and program another. Fortunately, if we do get that far, I have friends, and some of them really like doughnuts.

So I’m not saying there is an easy solution to a CPU failure, I’m just saying post a good photo of an exposed board and let’s have a look.
Dave

RonSSNova

I can get better if you like. As close as you like.
The devices in question aren't SMD. More than likely BGA flip chip devices with underfill. Very difficult to rework. If not impossible.

Removing the substrate from the housing would also likely be near impossible w/o cracking it. Shoot, cracked substrate might be the real issue. Except the crack would be VERY hard to see.

Ron

madmatt9471

Ron,
What year is this one off of?

I still have that other one in the box on the shelf for use too!

With that one if it were to sit for a few hours with the power unclipped and let cool down it would work for about 15-30 miles depending on road conditions etc. sometimes it wouldn't it would just set even on a decent smooth road.

But I do have it still!

Thanks,Matt

RonSSNova

This is an ABS only unit, not AH. I believe it is from a 99? Not sure, I don't have it here, and it was given to me by Vettenuts.

I bet yours could be fixed.....no guarantees, but it has an intermittant. Heat related at that. I know, re-route one of your AC ducts up front to it so it stays cool all the time.....

I'll have time to play with this stuff over the winter. I'll ping you and you can send it up! Easy enough to take apart and check the obvious.

Ron

madmatt9471

Right on! Let me know and I will get it out and in the mail!

Thanks,Matt

FL_Dave

Thanks Ron. I'm eating crow over here! Indeed this is a tough rework, and no markings on the chip. Bugger.

I appreciate reading the more informed answer, even if it isn't mine. I can't speak to the number of shops able to R&R BGA and don't have a good plan, off the top, to make progress on failed modules.

Are any forum members aware of instances where GM has licensed proprietary designs on Corvettes to outside houses? I know it is a stretch but otherwise we're left with salvaged units or lucky fixes on intermittent failures.

Dave

RonSSNova

No crow eating. They are too hard to cook!
I need to get back with the Failure Analysis folks and at least try to get the goo out. Nothing to lose on the module we have to play with.

Bill Curlee

Dave

If I were a guessing man and put a little GM Logic behind that question, heres how I see it.

You would have to ask the question to the correct person who could filter it up thru people who could see the benefit in letting the info go.

As I see it,, NO ONE at GM has a remote idea that this is an issue and doesn't even care about legacy issues. They are more concerned about the C7 and VOLT!

We have to let them know that its becoming a serious C5 legacy issue and theres a need to resolve it.

If the correct person is asked to look into it,, I would guess that they would contact the correct people and they would most likely bid out the rights to the design data, programming and process and have some share in licensing and profit. Gotta reduce that red line profit loss some how...

Bill

RonSSNova

How to find the "correct" person?

An inside track would be the best bet, but it doesn't seem like anyone on this board knows that person.

The other possibility I see is that someone does know this person, or persons, and will see it as a money making opportunity and isn't going to tell us any details to get moving on this. Sorry, but we live in a greed based economy.

This info all exists inside GM somewhere.

Ron

Bill Curlee

Ron

Its not knowing the person that says DO IT.. Its knowing the person that is a GM Insider that is willing to push the idea UP the Chain Of Command to that DO IT person.

I may have a microscopic bit of access and will see if I can get it to pan out. All I can do is ask. Dont get your hopes up.

Bill

Phanni

Bill, what would be involewd in order to upgrade and early C-5 to the newer technology of the 2001+? EBCM, harness, reprogram, etal...Surely it isn't an unsurmountable task..

0Chuck CoW

Bill Curlee

Excellent job Chuck!

Bill

CactusCat

This is some really great hopeful news. Way to go COW!!! Lets hope this leads to an assured repair in the very near future.