Alan Humphrey

After 2 months of trying to determine what caused my 1996 LT4 interior lights/systems to just completely die, I diagnosed as a faulty CCM. CCM's are no longer built and GM does not offer for sale any longer, so I purchased a used one off of ebay, knowing I would have to get it reprogrammed. I installed it and it did fix the problem as it relates to all the systems working; I just can't start the car as the VATS system is preventing it from starting. But, the LCD and all other systems that were dead are now lit up and ready to go.
My understanding is that the CCM must be reprogrammed by a Tech1A.
My questions are this:

1. When getting the replacement CCM programmed, can the VATS code be reprogrammed into it? If so, can the mileage and VATS code be downloaded from the faulty CCM and input into the replacement CCM? (I don't know the VATS code, but I can determine that by checking the resistance on the key)
2. When programming the CCM, does the Tech1a plug into the OBD port or is it reprogrammed by plugging into the CCM directly, as the CCM has 2 plug-in ports? Can the reprogramming be done without the car or does the CCM need to be plugged into the car?
3. Does the CCM store the VATS code? If so, the dilemma I face is that I don't know the VATS code to the replacement CCM and although I can determine my key resistance, would I have to replace the ignition switch with a key code that matches the replacement CCM? (I have watched a video online as to how to fairly easily bypass the VATS system, but my key does not match the replacement CCM.) Don't know what to do or can the CCM be programmed with my key?
4. I have read that a CCM must be reprogrammed within 100 miles; does this apply to a used CCM or does that refer to one that has been rebuilt and zeroed out? I would like to input the correct mileage into the replacement CCM as the replacement CCM has more miles on it than the correct mileage of my car.
5. Last but not least, and the most important question: Where can I find someone that can program this thing???? I checked the Chevrolet dealership and a couple of other mechanics in town, and they don't even know what a CCM is. So, I don't want to let them touch it if they don't even know what it is or what it does.
6. Is this something that is as easy as plugging in a Tech 1A, and entering mileage, options, etc? If so, maybe I should just find a used Tech 1A with the proper software? Maybe the problem lies in that nobody has a Tech1A?

Any help would be greatly appreciated.
Thanks,
Alan

WVZR-1

Once the miles and VIN are in a CCM it can't be reprogrammed for 'OTHER'. If you're happy with the miles and aren't concerned with VIN I'd suggest you find someone with a VATS INTERROGATOR and have them sort the current CCM 'resistance' and make a new key.

You could do it manually if you've patience.

Where are you located? I have an Interrogator and I believe a few others do also.

Alan Humphrey

So, the VIN and mileage can't be programmed?
I don't mean to disrespect or question you, but I have read on this forum in different threads from multiple people saying the CCM could be programmed; so, now I am really confused.

The VIN doesn't bother me so much, but the mileage of this CCM I purchased is 30K more than what the car has, and I plan on selling it. So, that would devalue my car considerably. I have seen a couple of companies online that "reprograms" for $495 or $269; you have to send them your CCM along with the mileage and VIN and they send it back; I wander if they are legit?
Or, I could find another used CCM with closer to 78K miles and I would be happy, but I still would have the VATS issue.
I haven't read about this VATS Interrogator you mentioned.

drcook

Have you checked into this:

https://corvetteparts.com/item/repai...e-ccm-bcm-1996

Alan Humphrey

Yes, this is one of the places online I had run across. I will need to check into further I suppose. However, I do value WVZR-1's opinion as he is a senior member here.

drcook

Most folks, including myself do, however, a phone call costs nothing to see if they have new developments.

Also take into consideration the statement

So they are not altering another module and changing values.

ChumpVette

1) Once a CCM has been programmed for cats/miles, it can not be reprogrammed. It is locked until wiped and start from scratch.

2) Programming is done with the ALDL port. Anybody who repairs and reprogram has a bench setup with the appropriate wires/connectors.

3) Yes the CCM burns the VATS code into memory. Good luck finding out the code on your replacement. A good salvage yard would have given you the code.

4) 100 miles is for new CCMs only.

5) Have no idea who to recommend as you haven't filled out your profile with a location. There are a few of us on the forum with the tools and know how to do the programming.

corvette95

This and WVZR-1 are correct

drcook

where does it say new ?

specifically says rebuilt from core
specifically says performed on the existing module
specifically says the service is to repair the faults

says it will check to ensure the unit is correctly programmed

anesthes

Did anyone call them and ask?

I'm assuming they wipe the flash somehow, perhaps even replace it, tricking the unit into being "new" again.

-- Joe

Zip Corvettes

We can with our rebuild process. The mileage is not programmable at all, it stored between the ECM and dash as well. The Vats will be blank and there is a setup procedure that will require all keys to be present. We build a bunch of these and the cores are really hard to get so it is a service. You have to send yours in to get rebuilt.
Justin

WVZR-1

I doubt this!!

You might 'sublet' several but I seriously doubt that they're done 'in house'.

ChumpVette

Is the mileage just floating around in the wiring?

Zip Corvettes

No we do not do these in house, they are done down the road from us from the guy who figured out how to do them and owns about the only machine left to run one on a bench..... YES WE GO THROUGH A TON OF THEM.

Zip Corvettes

I don't remember saying wiring? I did say dash and forgot to put Cluster behind it. Are you asking or being sarcastic?

ChumpVette

Extremely sarcastic.

The mileage is only contained in the CCM. The cluster contains nothing other than a LCD screen that displays what the CCM tells it to. The ECM contains no info regarding mileage.

anesthes

So to be clear. If mine dies, or I'm doing a dash swap. If I send you a CCM, you can fix/program/whatever it to my VIN and mileage ?

-- Joe

corvette95

Wow, you really do not know what your are talking about. Do you know what year the Corvette introduced the CCM (not BCM BY the way). Do you when the Tech1 or Tech1A came out? Looooooong before then. The CCM is the ONLY place mileage is stored from 90 on up. A new CCM (don't know about your reman's) could be programmed with correct VIN, Key resistance , AND mileage for up to the first 100 miles There are minor exceptions about ignition cycles and key resistance. Best not to poke the monster, lot's of knowledgeable people here. We just don't post that often, but you sir are wrong and would do well for your reputation to research this and apologize for posting incorrect information.

Zip Corvettes

Mr Corvette95, you keep believing that. I am not going to argue with you or any of the "experts" on here. You need to do your research because you are not correct on this. Also, it is 1990 and I own a Tech 1A. Since I lack the knowledge I guess, who is it do you think that cracked the code on the rebuilding the BCM/CCM in the C4's?

corvette95

From what what you have posted it appears you certainly haven't cracked the code or know what you are talking about, now go on about your business of ruining the few good cores that are out there.