HELP, I erased the flash in my PCM

[Tom Hussey]

Hi Dave,

To reprogram an ECM with a clean flash that has been powered off there
are only two ways I know of...

1) Replace the FLASH

2) Use the CPU bootstrap mode. To do this you need to force the mode
pins then do reset. This places the CPU in a mode where you can download
a bootstrap to internal ram. Use this bootstrap program to reprog the
FLASH. For all the info on this see Motorola AN1010 and AN1060. From
what I understand, bench mode won't work
Please tell me the address you used to turn on VPP. Those details would
be of great interest to me.

-Tom

Beth Hempstead wrote:
> 
> Please help me!!!
> 
> I wrote alot of complex code (with at least 1 bug in it) which
> successfully erased the flash in my '94 GM PCM, but did not
> successfully re-program it with new bits.  Therefore, I have a PCM
> which is dead.
> 
> I realize that I can unsolder the flash, reprogram them, and solder
> (or socket) them back in the PCM.
> 
> Is there any easier way to get the PCM back to listening to the
> ALDL????  I can easily open it up.
> 
> What do you experts do when they try to reflash a PCM, and you get a
> glitch, power failure, or some other error code.  I doubt that you
> throw it away.  How do you recover the PCM???
> 
> 
> Any help will be GREATLY appreciated
> Dave (boy do I feel stupid) Hempstead
> (formerly) '94 Caprice PCM 16188051