[V8] Who Works on ECUs?

[urq]

... who's telling you anything about the speed sensor?  If anyone is, I'd 
ask them to prove it to you ... if you lose the speed sensor signal the 
engine can't run ... end of story ...

Your note about the fact the ISV needed to be replaced due to a short was 
interesting, I don't know if I knew that ... if that condition lasted for a 
long time it very well may have damaged the electronics ... and that may be 
why you see the difference between the two ECUs.

"Who works on ECUs?" ... I suspect the answer to the question is noone.  The 
ECU in the V8 has got two circuit boards inside with a good bit of surface 
mount circuitry.  To work on it reliably would require having schematics ... 
or at the very least a block diagram.  I've picked up a couple spares as 
I've found them over the years ... best source is someone parting out a car. 
You could probably get a rebuilt unit from the dealer ... or check the phone 
book for automotive electrical repair shops that claim to handle Bosch ... 
they just might be able to get what they need to fix it.

... when you do get to swapping chips, make sure you know how to get the 
circuit boards apart ... the upper circuit board holds one row of pins for 
the external interface connector, and you've got to do some fancy footwork 
to disengage the pins from the connector ...

Steve B
San Jose, CA (USA)

----- Original Message ----- 
Bad back has forced me to take it into a reputable shop (not sure which
hurts more), so I don't have all answers at my fingertips.  They did look
for vacuum leaks and checked the cruise control.  Accelerator cable was
binding slightly and has been replaced.  The ISV is new; old one was
throwing a code (short to ground) and had about 70k miles on it, and
cleaning had no effect.  Speed sensor is also new.

I'll ask whether idle changed when unplugging ISV but assume that it did.
It really sounds like when the speed sensor input gets screwed up, the ECU
clamps the idle output.

So does anyone know who works on these (my soldering skills are mediocre,
and the shop has the car) or what is a reasonable price from a yard?  Sounds
like a computer from an automatic should be ok, and I should be able to swap
the chips.