Is this a stock chip?

[mrpip]

Hi all.
I just opened up the ECU to install a SW chip on my '88 Carrera and this was in there. SW's instructions note that the stock chip will have a number on the foil sticker whereas mine doesn't. TIA,
Pip.

[difparis]

No, that's not a stock chip.

[steely]

agreed - it's an Eprom from Signetics (S) with a window sticker from Texas Instruments (TI) (unusual).
There should be a nice long number on the sticker.
Maybe Steve will read it for you and let you know if it is a copy of the original map or something else.

[difparis]

This what a stock chip looks like

[mrpip]

ok thanks for the responses guys. it also appears the soldered in "chip" above it is from TI too. strange!
has anyone seen that chip changed/upgraded before and what may be the reason?

[steely]

S703 is an A/D converter.
I can't say if it was changed or stock because I don't know, but there is some interesting stuff here about the DME if you want to browse it: Inside a Carrera ML3.1 DME - Dorkiphus.net

[mysocal911]

Originally Posted by steely

S703 is an A/D converter.
I can't say if it was changed or stock because I don't know, but there is some interesting stuff here about the DME if you want to browse it: Inside a Carrera ML3.1 DME - Dorkiphus.net

It has the Bosch part number (B57427), so most likely it hasn't been changed unless it was "pulled"
from another Bosch ECU and installed in that one. And there aren't non-stock A/D chips being used,
i.e. an A/D is an A/D.

[steely]

Originally Posted by mysocal911

It has the Bosch part number (B57427), so most likely it hasn't been changed unless it was "pulled"
from another Bosch ECU and installed in that one. And there aren't non-stock A/D chips being used,
i.e. an A/D is an A/D.

Interesting - I did not know that there was a Bosch number assigned and that chip mfrs went to the trouble of putting a client's own number on their ADC's - especially since an A/D is an A/D and that there were several (unknown to me) ADC mfrs' to select from. Good to know that the OP has an original.

[mysocal911]

Originally Posted by steely

Interesting - I did not know that there was a Bosch number assigned and that chip mfrs went to the trouble of putting a client's own number on their ADC's - especially since an A/D is an A/D and that there were several (unknown to me) ADC mfrs' to select from. Good to know that the OP has an original.

The Bosch part number only marking may result from:
1. a special temp range parameter screening
2. a certain data rate, etc. screening
3. to reduce reverse engineering ability
4. easier inventory control