[Diy_efi] NVRAM chip for a 1986 GM odometer?

[Scot Sealander]

I am not sure if you are asking a question or just stating your experience.

> Not so hot reliability for the panel to go *poof*
> at only 96,480 miles.

Well, a 21 year old electronics part starting acting funny?  Seems to me to
be fairly reliable!  I would offer a guess that maybe the solder was
fractured somewhere.  There is also the possibility that the EEPROM has just
been written to too many times.


> Would be nice to find a reasonably priced replacement
> and a way to set the miles to match the original.

Sure, but if it was easy to reset the mileage, we would have lots of
low-mileage used cars around.  I think GM kept this part quiet for a reason.
Do you know what the NVRAM part is?  There is a good chance that it is a
house marked EEPROM that could be replaced, if it is still available.

Scot

-----Original Message-----
From: diy_efi-bounces at diy-efi.org [mailto:diy_efi-bounces at diy-efi.org] On
Behalf Of Gregg Eshelman
Sent: Wednesday, July 04, 2007 4:49 AM
To: diy_efi at diy-efi.org
Subject: [Diy_efi] NVRAM chip for a 1986 GM odometer?

I was pointed to this list from the V6 J-body list.

I have a 1986 Cadillac Cimarron with the digital
instrument panel. It developed a bunch of problems
suddenly (trip meter quit, displays intermittent,
english/metric switch stuck on english) so I sent it
off to the only place I could find that would work
on this particular panel.

A bit later the tech there calls and said it's all
fixed except the odometer. When he first powered it
up it displayed all zeroes, a common problem. (Just
before I sent it off, I hooked it up to check the
miles and it read 96480.) After he did the repairs,
the odometer read ERROR. He tried the NVRAM chip
from the Cimarron cluster he has that he's been
cannibalizing parts from and it too said ERROR.

Says he can't get those chips, that particular one
was only used in the Cimarron. Going through a GM
dealer to have AC Delco refurbish my already
refurbished panel (and have the NVRAM chip replaced)
would cost me $300! AC Delco does not sell just the
chips, repair or exchange of the whole panel only.

The service manual for this car says the odometer
will read up to 200000 miles then will display FULL.

Not so hot reliability for the panel to go *poof*
at only 96,480 miles.

The panel is still in transit by UPS back to me, so
I can't get numbers off the chip yet.

Would be nice to find a reasonably priced replacement
and a way to set the miles to match the original.
I'll be keeping mileage logs until I can get the
odometer fixed!