Cars - Junkyard Engine Computer Issues

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Junkyard Engine Computer Issues

I think the PCM (powertrain control module) in my 1998 Grand Voyager,
3.3L w/anti-theft is bad, and I'd like to swap in one from a junk yard.

In reading what I can find on the net, it seems like this should work.
It sounds like there are problems with the BCM (body control module) if
it does NOT have the anti-theft option and the replacement PCM DOES.
But I do have anti-theft, so it sounds like if I get a non-anti-theft
PCM it will not damage anything.

However, I'm wondering about my VIN number and odometer readings. Will
those come from the junkyard PCM? If so, how can that be corrected?

It would be worthwhile to me to verify that the problem is the PCM by
swapping in a used one, even if I have to buy another one from the
dealer or pay to have the junk one reprogrammed.

The junkyard PCM's can be had for ~$100, sounds like one from the
dealer will cost many times that.

I think my PCM is bad because it behaves erratically even when I just
turn the key on, with the ASD, fuel pump, and purge valve relays
clicking wildly.

Battery is good, cranks well and measures 13.4V after charging. Cleaned
battery cables, checked fuses, reseated power distribution and PCM
connectors.
-Paul

Junkyard Engine Computer Issues

Try Ebay first. I bought a Honda Accord PCM for 29 bucks.

Junkyard Engine Computer Issues

wrote:
> I think the PCM (powertrain control module) in my 1998 Grand Voyager,
> 3.3L w/anti-theft is bad, and I'd like to swap in one from a junk yard.
>

Update on this. I searched for compatible engine computers online:
http://www.car-part.com/

and found 10 or so. There was a huge variation in price, from $500 to
$65, I ordered the $65 unit from All West Coast Auto Wrecking in
Washington.

They sent me the wrong part, a transmission computer. Easy mistake to
make, that one is on the right fender, the correct part is mounted on
the left fender. I figured I'd get the run around, but they said they
had the right part, and just send back the wrong one, which I did. I
expected it to take a week for them to receive my package and send me
the correct part, but they shipped without waiting so I got it in 3
days.

I plugged it in, and it fixed the problem. So I guess I still have to
buy one from the dealer with the correct VIN programmed, but I can take
my time and won't have to pay a fortune for troubleshooting and having
the wrong parts replaced. In fact, I may take a crack at the bad
computer. I'm an electronic tech by trade, if I can get the potting
compound off I may be able to troubleshoot it. I suspect a voltage
regulator, since the problem affected all parts of the computer.

Oh, I should mention that in searching the net, I found that a lot of
people with a similar problem had fixed it by reflowing the solder on
the instrument cluster connectors. There was a ground that tended to
crack on the 1996-2000 minivans. Their van would suddenly quit and
refuse to start, and they could get it going by pounding on the dash.
So I pulled the instrument cluster, but could see no fractured solder
joints. I reflowed the solder on the cable connectors anyway, but it
didn't help in my case.

Hope this helps someone down the road with one of these problems.
-Paul

Junkyard Engine Computer Issues

--

> wrote in message
oups.com...
>
> wrote:
> > I think the PCM (powertrain control module) in my 1998 Grand Voyager,
> > 3.3L w/anti-theft is bad, and I'd like to swap in one from a junk yard.
> >
>
> Update on this. I searched for compatible engine computers online:
> http://www.car-part.com/
>
> and found 10 or so. There was a huge variation in price, from $500 to
> $65, I ordered the $65 unit from All West Coast Auto Wrecking in
> Washington.
>
> They sent me the wrong part, a transmission computer. Easy mistake to
> make, that one is on the right fender, the correct part is mounted on
> the left fender. I figured I'd get the run around, but they said they
> had the right part, and just send back the wrong one, which I did. I
> expected it to take a week for them to receive my package and send me
> the correct part, but they shipped without waiting so I got it in 3
> days.
>
> I plugged it in, and it fixed the problem. So I guess I still have to
> buy one from the dealer with the correct VIN programmed, but I can take
> my time and won't have to pay a fortune for troubleshooting and having
> the wrong parts replaced. In fact, I may take a crack at the bad
> computer. I'm an electronic tech by trade, if I can get the potting
> compound off I may be able to troubleshoot it. I suspect a voltage
> regulator, since the problem affected all parts of the computer.
>
> Oh, I should mention that in searching the net, I found that a lot of
> people with a similar problem had fixed it by reflowing the solder on
> the instrument cluster connectors. There was a ground that tended to
> crack on the 1996-2000 minivans. Their van would suddenly quit and
> refuse to start, and they could get it going by pounding on the dash.
> So I pulled the instrument cluster, but could see no fractured solder
> joints. I reflowed the solder on the cable connectors anyway, but it
> didn't help in my case.
>
> Hope this helps someone down the road with one of these problems.
> -Paul
>

Actually if you take the back cover off, plug the PCM back into the vehicle
and wiggle the aluminum tower like thing that looks like cooler (I have no
idea what it is) the engine will probably start and run until you wiggle it
again, this is a common problem with those PCM's. Even the ones that MOPAR
Remanufactures (by a sublet company) get put back out on the market with
these problems. Try it and let me know if it starts

Glenn Beasley
Chrysler Tech

Junkyard Engine Computer Issues

maxpower wrote:
> --
>
> > wrote in message
> oups.com...
> >
> > wrote:
> > > I think the PCM (powertrain control module) in my 1998 Grand Voyager,
> > > 3.3L w/anti-theft is bad, and I'd like to swap in one from a junk yard.
> > >
> >
> > Update on this. I searched for compatible engine computers online:
> > http://www.car-part.com/
> >
> > and found 10 or so. There was a huge variation in price, from $500 to
> > $65, I ordered the $65 unit from All West Coast Auto Wrecking in
> > Washington.
> >
> > They sent me the wrong part, a transmission computer. Easy mistake to
> > make, that one is on the right fender, the correct part is mounted on
> > the left fender. I figured I'd get the run around, but they said they
> > had the right part, and just send back the wrong one, which I did. I
> > expected it to take a week for them to receive my package and send me
> > the correct part, but they shipped without waiting so I got it in 3
> > days.
> >
> > I plugged it in, and it fixed the problem. So I guess I still have to
> > buy one from the dealer with the correct VIN programmed, but I can take
> > my time and won't have to pay a fortune for troubleshooting and having
> > the wrong parts replaced. In fact, I may take a crack at the bad
> > computer. I'm an electronic tech by trade, if I can get the potting
> > compound off I may be able to troubleshoot it. I suspect a voltage
> > regulator, since the problem affected all parts of the computer.
> >
> > Oh, I should mention that in searching the net, I found that a lot of
> > people with a similar problem had fixed it by reflowing the solder on
> > the instrument cluster connectors. There was a ground that tended to
> > crack on the 1996-2000 minivans. Their van would suddenly quit and
> > refuse to start, and they could get it going by pounding on the dash.
> > So I pulled the instrument cluster, but could see no fractured solder
> > joints. I reflowed the solder on the cable connectors anyway, but it
> > didn't help in my case.
> >
> > Hope this helps someone down the road with one of these problems.
> > -Paul
> >
>
> Actually if you take the back cover off, plug the PCM back into the vehicle
> and wiggle the aluminum tower like thing that looks like cooler (I have no
> idea what it is) the engine will probably start and run until you wiggle it
> again, this is a common problem with those PCM's. Even the ones that MOPAR
> Remanufactures (by a sublet company) get put back out on the market with
> these problems. Try it and let me know if it starts
>

That's a good tip, I can see you know your stuff. I tried that already,
I found some info online that said the solder joints on the connectors
can crack, so I was in there pushing on everything thru the potting
compound while my wife worked the key. Didn't make any difference.

Something is drawing a lot more current than on the good computer,
though, so I have a chance of zeroing in on it. Most likely it is one
of the devices connected to the "silver towers", which are heat sinks.
The parts that get hot are mounted on them, so they're the ones that
tend to fail, and they're most likely voltage regulators. Peering thru
the amber potting compound, the one at lower left looks like a
switching power supply, it probably makes 5V out of 12V.

Thanks for the reply.

-Paul

Junkyard Engine Computer Issues

Well, why would you get another one with your vin encoded in it? The one you
have is working, so it would seem pretty stupid to spend the money on one to
get the vin encoded on it? Especially since your vehicle is no longer under
warranty.

Junkyard Engine Computer Issues

wrote:
> Well, why would you get another one with your vin encoded in it? The one you
> have is working, so it would seem pretty stupid to spend the money on one to
> get the vin encoded on it? Especially since your vehicle is no longer under
> warranty.

I'm in California. I'm told it won't pass my biannual smog test which
is all computerized to prevent fraud. The car's a giant paperweight if
it won't pass the smog test.

I'm going to try to fix the old one, since I'm an electronic tech.
Meantime, I can drive about a year until the next smog test is due.

I'm actually pretty happy to have it driveable again, and know for
certain what the problem is. I pictured getting ripped off for
thousands of dollars as the dealer changed part after part.

-Paul

Junkyard Engine Computer Issues

I'm in Arizona and have to go for emissions every few years also. The only
thing they are worried about with the computer, is that they can plug in the
scanner to prove there are no engine codes.

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Junkyard Engine Computer Issues