Dead computer - can it be rebuilt? - need advice

Hi all,
I've got a pretty much stock 95YJ with around 140,000 miles on it. The
other day, as I was driving, the Jeep turned itself off. It didn't stall
out, just shut down. The battery had juice and I had a half tank of gas.
I tried to re-start but all it would do is crank over and over - nothing
ever caught.

I took it to a repairman and I was told the computer is dead. I'm
presented with the option to have the computer sent out for rebuilding
(its estimated at about $700).

Can the computer be rebuilt? Does this sound legit? I've got to give the
dude an answer soon as to what to do, and would like to hear from more
knowledgable people.

Thanks

-Art

The most common, and it's 'really' common cause for that is just a dirty
connection on the CPS on the bell housing. The plug and socket sit
right on top of the exhaust manifold and corrode easy. A good spray
with an electronic contact cleaner fixes them.

Another very common one that causes the same symptoms is a dead body
ground strap. It goes from the rear of the head to the firewall and
when they quit, it just shuts down the computer.

The last one is a bolt above the dipstick with some small black wires on
it. This is the computer sensor ground tag.

The main computers almost never fail. It happens for sure, just not
often.

Even just unplugging the CPS and plugging it back in will usually get a
start. If you do this and it fires up, you have found the trouble.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

Artur Jorge Duque wrote:
>
> Hi all,
> I've got a pretty much stock 95YJ with around 140,000 miles on it. The
> other day, as I was driving, the Jeep turned itself off. It didn't stall
> out, just shut down. The battery had juice and I had a half tank of gas.
> I tried to re-start but all it would do is crank over and over - nothing
> ever caught.
>
> I took it to a repairman and I was told the computer is dead. I'm
> presented with the option to have the computer sent out for rebuilding
> (its estimated at about $700).
>
> Can the computer be rebuilt? Does this sound legit? I've got to give the
> dude an answer soon as to what to do, and would like to hear from more
> knowledgable people.
>
> Thanks
>
> -Art

Mike Romain wrote:
> The most common, and it's 'really' common cause for that is just a dirty
> connection on the CPS on the bell housing. The plug and socket sit
> right on top of the exhaust manifold and corrode easy. A good spray
> with an electronic contact cleaner fixes them.
>
> Another very common one that causes the same symptoms is a dead body
> ground strap. It goes from the rear of the head to the firewall and
> when they quit, it just shuts down the computer.
>
> The last one is a bolt above the dipstick with some small black wires on
> it. This is the computer sensor ground tag.
>
> The main computers almost never fail. It happens for sure, just not
> often.
>
> Even just unplugging the CPS and plugging it back in will usually get a
> start. If you do this and it fires up, you have found the trouble.

To add to what Mike said, a re manufactured ECU is a lot cheaper than
$700. A quick check of http://www.ecudirect.com shows a price of $250,
and since they rarely fail I would imagine one could be had from a junk
yard for much less. They are simple to replace but connectors and fuses
should be checked first.

--
jeff

Did the tech check for correct power going to the ECM. I have seen a large
fuse, possibly on a Grand Cherokee, cause a non-start issue. The fuse was
located in the engine compartment on the right side.

Also can you blink DTC codes with your Jeep? Or even plug into it with a
scanner?

How did the tech determine the ECM was bad?

Buy a good used one for checking purposes.

just some thoughts
--
later,
dave AKA vwdoc1

"Artur Jorge Duque" > wrote in message
mass.edu...
> Hi all,
> I've got a pretty much stock 95YJ with around 140,000 miles on it. The
> other day, as I was driving, the Jeep turned itself off. It didn't stall
> out, just shut down. The battery had juice and I had a half tank of gas.
> I tried to re-start but all it would do is crank over and over - nothing
> ever caught.
>
> I took it to a repairman and I was told the computer is dead. I'm
> presented with the option to have the computer sent out for rebuilding
> (its estimated at about $700).
>
> Can the computer be rebuilt? Does this sound legit? I've got to give the
> dude an answer soon as to what to do, and would like to hear from more
> knowledgable people.
>
> Thanks
>
> -Art

make sure the white wire witha yellow tracer has ing. battery voltage. if
there is none the vehicle will never start

jeff wrote:

> Mike Romain wrote:
> > The most common, and it's 'really' common cause for that is just a dirty
> > connection on the CPS on the bell housing. The plug and socket sit
> > right on top of the exhaust manifold and corrode easy. A good spray
> > with an electronic contact cleaner fixes them.
> >
> > Another very common one that causes the same symptoms is a dead body
> > ground strap. It goes from the rear of the head to the firewall and
> > when they quit, it just shuts down the computer.
> >
> > The last one is a bolt above the dipstick with some small black wires on
> > it. This is the computer sensor ground tag.
> >
> > The main computers almost never fail. It happens for sure, just not
> > often.
> >
> > Even just unplugging the CPS and plugging it back in will usually get a
> > start. If you do this and it fires up, you have found the trouble.
>
> To add to what Mike said, a re manufactured ECU is a lot cheaper than
> $700. A quick check of http://www.ecudirect.com shows a price of $250,
> and since they rarely fail I would imagine one could be had from a junk
> yard for much less. They are simple to replace but connectors and fuses
> should be checked first.
>
> --
> jeff