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Unread 02-01-2016, 07:54 PM   #1
jcooperdj
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How to take apart PCM / ECM 98 5.9

My PCM is not the same as the one in the write up here. Mine has a wrap around cover so it looks like it should slide apart but I do not think that is right. It has 4 torx screws on the front and 3 on the back. All I can see. It does not want to slide so how do you get in the thing to resolder it ?
Mine as NO tabs and the cover wraps around like a U shape.

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Unread 02-01-2016, 09:06 PM   #2
JonS
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Can you post some pictures?
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Unread 02-02-2016, 05:11 AM   #3
coralman
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It is correct. Its a different style pcm. I am not sure it was even made by motorola. I remember reading it was supposed to be a hardier pcm. Looks like this?

pcm.jpg

There is one like this on the yard I went to saturday. As to getting it apart I don;t know. I've seen this style on WJ's, and seem to remember a guy wasn't too successful trying to get it apart. Might look there abit.
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Unread 02-02-2016, 06:54 AM   #4
Marcos
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I sacrificed one of those getting it apart to have a look inside. The wrap around cover is glued to the frame, probably for sealing purposes. You'd have to pry and would end up bending the cover. The board inside is actually a large flexible plastic sheet/ribbon with all the surface-mount components, and it's glued to the wrap around cover as well. The board is wrap around too. Should have taken pics at the time.
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Unread 02-04-2016, 01:37 AM   #5
Candymancan
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That picture you posted looks like the normal PCM.. the only wrap around pcm i can find looks like this

http://www.ebay.com/itm/Jeep-Grand-C...-/111851628071
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Unread 02-04-2016, 11:24 AM   #6
JonS
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Quote:
Originally Posted by Candymancan View Post
That picture you posted looks like the normal PCM.. the only wrap around pcm i can find looks like this

http://www.ebay.com/itm/Jeep-Grand-C...-/111851628071
This is the "typical" 1998 PCM. You carefully straighten the tabs with a screwdriver and pliars, remove the 2 torx screws and use a hair blower to apply heat as you lift the top board out. This is the board that normally needs the fingers re-soldered (fingers 2,3). It comes apart fairly easily, buy go slowly.

From the OP's description, his sounds different. Need a picture of OP's PCM.
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Unread 02-04-2016, 02:59 PM   #7
ghiotom
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This what the inside of your PCM looks like. Like Marcos said, the "board" is actually a large flex cable and the traces are very tight.
20151025_202137.jpg  
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Unread 02-04-2016, 03:07 PM   #8
JonS
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I was referring to the top board:

image-1617440416.jpg
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Unread 02-04-2016, 04:51 PM   #9
coralman
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All I know is the 5.9 in the yard looked like my pic Thanks for those pics ghiotom, no potting,or its already off? Would like to know if the coil drivers are the same between both styles.
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Unread 02-04-2016, 05:05 PM   #10
ghiotom
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By his description, it sounds like the OP has the one in coralman's pic. That's the same one in my '96 5.2. I took out the Torx screws and pried it open like a book. There was no potting, just that grey silicone like sealant around the edges.
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Unread 02-05-2016, 07:08 AM   #11
Marcos
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Just curious if you put it back together after opening it up and put it back into service?
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Unread 02-05-2016, 04:41 PM   #12
ghiotom
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It was bad before opening (shorted out through rear O2 sensor harness rubbing on driveshaft). However, I did close it back up and sent it in for my core deposit on the A1 Cardone unit I got from RockAuto.
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