OBD2 LT1 XDF $EE EEX creation

[Tom H]

Hello guys...
I just read a couple of posts here (didnt haad time to read all completly but will try to) and for what i could read it seems that you guys are worrking on OBD2 LT1 ECMs...
If you allow me i can join the "test team" for the OBD2 LT1 ECMs...
I have one here that i would like to read / flash and see what we can do...
So, if you guys can point me out on where do i start, i will appreciate...
I also have a 95 LT1 ECM here, but there's some internal issues that dont allow to flash. I can read but when it comes to flash i have a VPP Error and it doesnt continue to flash...
For the OBD2 LT1, can we use the same USB-TTL cable or do we need anything else?

Thanks and i hope i can join in with the testing...

Thanks

Hi,
You are most welcome to the test team for both the LT1 ECMs. The procedure is for bricked (broken) ECMs and if your OBDII unit isn't broken, I think that there are much better tools to tune/work with the unit. Still if you want to try the UnBrick on it you absolutely can. So far I have just addressed the Eside, but that's a good start. I have not worked with the Tside because my test unit suffered a lobotomy. That is to say the ribbon cable that joins the two sides broke. I have been waiting for months for parts from china (now told that they are with Canada customs).
Regarding your '95 ecm with the VPP fault, this is interesting.You can use the UnBrick software to turn on VPP and debug the problem. The source of the problem may only be the A/D circuit that reads the value of VPP or it could be the actual level. A DVM reading from pin 13 of the ribbon cable will tell you quickly. Use the UnBrick and send the binary file that turns on VPP then take a reading on pin13. I have not yet discovered the part number for the regulator that produces VPP (perhaps someone knows??).

ESide Red/Black: Component side

    |
    |  29                             1
    |    0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
    |    0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
    |  30                             2
    |
     -----------------------------------

TSide Blue/Gray: Component side

    
        1                             29  |
         0 0 0 0 0 0 0 0 0 0 0 0 0 0 0    |
         0 0 0 0 0 0 0 0 0 0 0 0 0 0 0    |
        2                             30  |
                                          |
     -------------------------------------

There is a PDF among the files attached to the UnBrick discussion. Get the latest instruction pdf and work through it.

-Tom

PS: I should qualify the above, My info is based on a '97 unit. I believe the pin number will be the same. You can verify by testing for connection to the flash chip pin 1 on T or E side.