ECU question for the technically inclined...

Chris Pronios hpro@b-link.gr
Mon, 21 Oct 2002 09:22:36 -0500


OK. Things written on said items:

"Modified":        8.860
                       NDK.82

Stock Part:     8AMQ-8
                       TEW2L

> So now the question is, can you read the crystal's frequency from
> the modified board vs. from the stock board?

My guess here is that the modded part is something that runs at 8.86 MHz,
while the stock one runs at 8MHz, I am not sure though and I did not have
time to search for actual info on above.

>...I'd think it
> would be dangerous to increase the clock frequency since that could
> create timing problems if something depends on that frequency to
> derive a concept of "real time", or to talk to other components.

I wholeheartedly AGREE HERE. This was the motivation for my initial posting
and the reason I asked for anyone having any idea about "clock-signal"
modding.

I would never do it (if I knew it beforehand) on a daily driver, only for
testing purposes which I am about to do! Note however that the "host" car
for this modded ECu has been running happily (over 2 years) with the modded
part. Of course I cannot know what might happen anyday now.

> Are you sure that's the only part that's been touched?  Maybe it
> was just repaired before it left the factory?  Crystals are somewhat
> fragile and during the stresses of board manufacture they do fail
> sometimes, requiring repair.  That wouldn't be unusual.  (Seems like
> when I did this kind of stuff years ago it was about 1 in 1000?)

Steve, if the factory actually did such a butcher job of soldering I may
re-consider my opinion on Nissan quality. The moment you look at the bottom
of the ECu board the soldering stands out as if they de-soldered,
re-soldered and all over again 2-3 times. It's gross!.

Chris