Corvette CCM Reverse Engineering Anyone?

[AngryCorvair]

Sure did! It was a ragtop with 200k miles, had been painted 3 times - a different color each time - and was on a buy here pay here lot. I made more in parts sales than I paid for the car, and kept everything I thought I might need for getting the LT1 up and running in the Corvair. I’m finally at the point of wiring the car and found this thread in my reading of 200 pages of GM EFI threads. C42CCFC8-79E2-4E91-9B02-947F4E59592A.jpg

[In-Tech]

Do you have the suspension left? Front and/or rear? I am getting ready to do a vette suspension in a '56 Chev PU

[-=Jeff=-]

Hi all,

NomakeWan pointed me here.. While I am still reading through this thread (currently on page 9) I have some questions and will offer some Help

Including my car (1990 ZR-1) I have 4 CCMs, 2 1990s (both ZR-1 programmed) one 1991 (I think) and one 1992. I know the 1992 is programmed for a LT1 and I want to change it to LT5 and adjust mileage to match my 1990 as i would like to move to the 1992 coding to allow for the additional gauges on the LCD.

I am curious if you have been successful in reprogramming the CCM.. if so I would like to try it..

I am willing to get dumps from the CCMs I have, but not sure how to do that.. but happy to if I can

[NomakeWan]

Getting a dump from your LT5 CCMs would be phenomenal, as would if any of your 4 CCMs were from cars that originally had C60 climate control (manual). I know you have a C60 unit installed in your car right now, but I'm guessing it didn't actually come that way from the factory.

To dump the CCM, you'll need to plug a laptop into your ALDL port and use steveo's flashhack software. It's available here: https://ecmhack.com/flashhack/#Downloads

When you run the program you'll be greeted with a selection window. Choose "ALDL Universal Read" and then click "Run." Then go to Parameters tab -> Device ID and change the value from f4 to f1. Then go back to the Operations tab and click Read Calibration. This will download the entire CCM. You can then save the BIN and toss it up as a forum attachment.

[spfautsch]

NomakeWan I see you added an eeprom car to your collection - cool! Anyway, thanks for helping -=Jeff=- get started dumping memory.

Jeff - it's been a while and I've moved on to other projects so I might be slow to respond but will do everything I can to help. When you get the memory dumped post them up along with everything you know about them except the mileage as I'd like to verify my assumptions without bias of knowing ahead of time.

I've definitely been able to reprogram the '95 CCM. I currently have a '94 along with the harness side connectors thanks to AngryCorvair but have yet to take the time to re-assemble my test bench to dump it's memory. Having the memory dumps from yours will be very beneficial for owners of eeprom based cars (93 and older LT1s, all ZR-1s).

Disclaimer - you will have to open the unit up and short the reman pin to ground to be able to unlock the CCM, but I'm sure NomakeWan mentioned this. I'm sure you also know that getting them out of the car is no picnic.

I cleared up some space in my inbox so PM is now available again.

[-=Jeff=-]

Getting a dump from your LT5 CCMs would be phenomenal, as would if any of your 4 CCMs were from cars that originally had C60 climate control (manual). I know you have a C60 unit installed in your car right now, but I'm guessing it didn't actually come that way from the factory.

Actually, 1990 is the only year to Offer C60 with the ZR-1 and C68 was an option. My 1990 is one of the rare C60 ZR-1s ( less than 200 ordered that way)

To dump the CCM, you'll need to plug a laptop into your ALDL port and use steveo's flashhack software. It's available here: https://ecmhack.com/flashhack/#Downloads

EDIT: just read this again, so it is on the same serial lines as the ecm, I can do this tonight hopefully, I can also get a 1992 CCM dump from a friend's ZR-1 at some point, it this is easy and no harm done on a dump, I might b able to get 1991-1995.. but no promises

When you run the program you'll be greeted with a selection window. Choose "ALDL Universal Read" and then click "Run." Then go to Parameters tab -> Device ID and change the value from f4 to f1. Then go back to the Operations tab and click Read Calibration. This will download the entire CCM. You can then save the BIN and toss it up as a forum attachment.

Nice, sounds easy enough.. How do I attach to the CCM for a Dump.. the other 3 are on the workbench

NomakeWan I see you added an eeprom car to your collection - cool! Anyway, thanks for helping -=Jeff=- get started dumping memory.

Jeff - it's been a while and I've moved on to other projects so I might be slow to respond but will do everything I can to help. When you get the memory dumped post them up along with everything you know about them except the mileage as I'd like to verify my assumptions without bias of knowing ahead of time.

I am not sure I know the exact mileage of each but know options

I've definitely been able to reprogram the '95 CCM. I currently have a '94 along with the harness side connectors thanks to AngryCorvair but have yet to take the time to re-assemble my test bench to dump it's memory. Having the memory dumps from yours will be very beneficial for owners of eeprom based cars (93 and older LT1s, all ZR-1s).

Disclaimer - you will have to open the unit up and short the reman pin to ground to be able to unlock the CCM, but I'm sure NomakeWan mentioned this. I'm sure you also know that getting them out of the car is no picnic.

I cleared up some space in my inbox so PM is now available again.

I have removed the CCM before.. it is not too bad (disclaimer.. my last C4 was an 89 in which I swapped to a 1991 full interior with working CCM)

What I would like is the digital data on the 92-96 LCD display, the 90-91 did not have it, but I know the wiring I need to change to allow the use of the 1992 CCM and 1992 PROM in the ECM to allow these features. so I really would like to switch form LT1 to LT5, I have a friend with a 1994, had a bad CCM and it was replaced before he bought it, but it was from an LT1 car, an I would like to help him by fixing that bit.

I would also like to correct the mileage of the 1992 CCM to match that of my 1990 when I do the switch, but that may not be an option

[NomakeWan]

Actually, 1990 is the only year to Offer C60 with the ZR-1 and C68 was an option. My 1990 is one of the rare C60 ZR-1s ( less than 200 ordered that way)

Woah, I didn't know that! What a rare beast! That CCM dump is going to be golden.

EDIT: just read this again, so it is on the same serial lines as the ecm, I can do this tonight hopefully, I can also get a 1992 CCM dump from a friend's ZR-1 at some point, it this is easy and no harm done on a dump, I might b able to get 1991-1995.. but no promises

The dump process cannot harm the CCM. The CCM rejects all attempts to harm it until you rip it out of the car and prod it. So yes, dumping these CCMs is perfectly safe, and highly appreciated! Would be awesome to see the differences between the 90-91, 92-93, and 94-96 CCMs.

Nice, sounds easy enough.. How do I attach to the CCM for a Dump.. the other 3 are on the workbench

See my pinout here: http://www.gearhead-efi.com/Fuel-Inj...ll=1#post90777

Note that there is a chance the older pinouts will be different. Best to confirm with the FSM if you have one. The point is you'll need power, ground, and the serial data pins. ALDL is a one-wire bus so just wire your USB-to-ALDL adapter to both serial data ports (if present).

I would also like to correct the mileage of the 1992 CCM to match that of my 1990 when I do the switch, but that may not be an option

It is absolutely an option.

NomakeWan I see you added an eeprom car to your collection - cool! Anyway, thanks for helping -=Jeff=- get started dumping memory.

Yep! Got it for a song, couldn't help myself. Not a fan of the L98, but definitely fun learning all this new stuff about the older cars. Guess it'll give me an opportunity to rewrite my LED conversion writeup to support the 84-90 cars too.

[-=Jeff=-]

I did the LED conversion.. for the headlights I added one relay to have full stock function with Fog lights..

I built a circuit to handle the amber side marker and allow turn signals to work.. I use switch back white/amber on the parking lights. lastly I have euro taillights all LEDs, no load resistors and everything works

[-=Jeff=-]

1990 ZR-1 with C60 Attached..

I downloaded the app but the XDF is only 0.9 Can someone post the more recent one? or can I get it.. I would like to know if it read the VIN or the Mileage correct

Just post the last 4 of the VIN in the BIN

[spfautsch]

The latest version of the xdf is in this post.

I have a handful of fires to put out this morning but will try to take a look at your '90 dump sometime today.

[NomakeWan]

The latest version of the xdf is in this post.

I have a handful of fires to put out this morning but will try to take a look at your '90 dump sometime today.

Unfortunately a forum update at some point appears to have nuked a great deal of attachments.

I just realized yesterday that I too own a 90. Unfortunately when I went to dump the CCM I found out the hard way that my 16-pin-to-12-pin adapter was Chinese junk that was improperly wired. In a few hours I'll go back out and just use jumper wires to get the job done.

[-=Jeff=-]

The latest version of the xdf is in this post.

I have a handful of fires to put out this morning but will try to take a look at your '90 dump sometime today.

As NomakeWan stated . the attachement looks to be there but it is not :(

[spfautsch]

Sorry, didn't bother checking if the link worked. Here's a direct link to the zip on my site.

Maybe I'll write up a page to hold this stuff and link to it in my sig.

[-=Jeff=-]

thank you!!

I will check out my CCM this weekend, and hopefully scan the other 3

[-=Jeff=-]

Just realized, that BIN dump si no good.. I forgot to do this:
go to Parameters tab -> Device ID and change the value from f4 to f1.