1227749 EEPROM Type

[TK]

Hi Scott,

You might be thinking that just because it's a 749, that the layouts for the
data on all cars using the 749 would be the same. No. The Syclone and
Sunbird Turbo are the same, but the Quad 4 is totally different.

Also, the Syclone use a 16k byte eprom (27128), whereas the Quad 4 uses a
32k byte eprom (27256).

So things vary a lot on applications using the same ECM.

Terry

----- Original Message -----
From: Scott Flanagan <flanaj at mindspring.com>
To: <gmecm at efi332.eng.ohio-state.edu>
Sent: Thursday, December 02, 1999 8:00 PM
Subject: 1227749 EEPROM Type


> While at the junkyard the other day I luckily came accross two '88
Pointiac
> Grand Am Quad 4's.  They have the 1227749 with the uncommon Integrated
> Direct Ignition.  I am trying to work with an old reader, but I am not too
> sure what type of chip it is, or if it is too odd to read.  The chip in
one
> of the ECU's has the number 27C256 on it, that is an original chip, which
> does not have a window for erasing.  My reader says it can read an I27256
> but it can't read it at all.  The other ECU is a remanufactured one, the
> chip does not have any numbers on it that are useful, but it does have a
> window for erasing things, my burner can read it but the information is
> garbled.  When loaded into Promgrammer it has some wacky values such as 0
> cylinders, etc.  Also, this is probably a dumb question but do you have to
> unsolder the chip from the long brown carrier?  Right now I have an
adapter
> that I made that connects the brown carrier to the reader.  Thanks, I am
> very excited that I could finally find these ECU's and complete harnesses.
>
>
>                             -Scott Flanagan
>
>
> '80 Fiat Spider (Awaiting new FI and Turbo)
>
>