1995 3.9L ECM removal and install??
#1
1995 3.9L ECM removal and install??
Hey guys, odds are you probably don't remember me but I've got the "possessed" truck. The one that if you slam any door, the hood, or hit a pothole... she dies! Well, I finally figured out the problem - the ECM.
When the engine is running, if you so much as even touch the ECM with your finger tip, the truck shuts down - just like if you slammed the door. I've taken off the front harness and cleaned it (my first logical conclusion) but I've still got the problem. Something's gotta be wrong inside of the ECM.
How do you properly remove the bad, and replace with a new? I've priced a new one out at O'Reilly's for just shy of $300 - not a huge investment and this truck is definitely worth it.
Any help is much appreciated!
~Jon
PS - I finally posted a pic up in the roll call page - yes, someone who owned this ugly beast before me actually put a Chrysler emblem on the front....
When the engine is running, if you so much as even touch the ECM with your finger tip, the truck shuts down - just like if you slammed the door. I've taken off the front harness and cleaned it (my first logical conclusion) but I've still got the problem. Something's gotta be wrong inside of the ECM.
How do you properly remove the bad, and replace with a new? I've priced a new one out at O'Reilly's for just shy of $300 - not a huge investment and this truck is definitely worth it.
Any help is much appreciated!
~Jon
PS - I finally posted a pic up in the roll call page - yes, someone who owned this ugly beast before me actually put a Chrysler emblem on the front....
Last edited by Littlejon126; 03-04-2010 at 04:10 PM.
#3
I don't remember you, so let me ask... have you checked the ASD and fuel pump relay power splice for corrosion?
Anyway, if you are 100% sure its the computer, its very easy to replace. Just unbolt the 60 pin connector, take out the 3 screws holding the computer down, put the new one in and reattach the 60 pin connector.
Anyway, if you are 100% sure its the computer, its very easy to replace. Just unbolt the 60 pin connector, take out the 3 screws holding the computer down, put the new one in and reattach the 60 pin connector.
#4
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If he can just go to the PCM connector, touch it, and it shuts off... I think he's tracked the problem down.
BUT, there is the possibility that the connector itself (not the PCM) is at fault.
Replacing the PCM, to find out the connector-side is loose (worn out, whatever), would be expensive.
Granted, replacing the wiring harness... with the PCM being the problem, would be a waste of time. Hmmm...
Is there a junkyard around you? Just wondering why you are wanting to buy one through a store.
BUT, there is the possibility that the connector itself (not the PCM) is at fault.
Replacing the PCM, to find out the connector-side is loose (worn out, whatever), would be expensive.
Granted, replacing the wiring harness... with the PCM being the problem, would be a waste of time. Hmmm...
Is there a junkyard around you? Just wondering why you are wanting to buy one through a store.
#5
Junkyard was actually my first thought. I might can make a trip sometime during the week and see what I can pull.
Another indicator that the ECM is the problem is that on occasion, after it dies (from a pothole, door slam, or other jarring) sometimes the check engine light does not come back on when attempting to restart when the they key is on, but the engine is off. I've found that it only does so if that startup check engine light is functioning properly. That was really my first thought, and that I noticed that the truck was more sensitive to a pothole or door slam on the passenger side, where the ECM is located.
I'll check out a junkyard and see if I can find anything... Thanks guys! I'll be back soon, with pictures of the repair.
Another indicator that the ECM is the problem is that on occasion, after it dies (from a pothole, door slam, or other jarring) sometimes the check engine light does not come back on when attempting to restart when the they key is on, but the engine is off. I've found that it only does so if that startup check engine light is functioning properly. That was really my first thought, and that I noticed that the truck was more sensitive to a pothole or door slam on the passenger side, where the ECM is located.
I'll check out a junkyard and see if I can find anything... Thanks guys! I'll be back soon, with pictures of the repair.
#6
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#8
I had issues with my 91, 318 4x4. It would run fine ( for awhile ) a then quit. I'd have no spark ( checked and fixed the usual screwed up factory splices ). It would start and then quit again.
I figured it was the ECM. My local dealership didn't have another ECM I could try without buying it. The local wrecking yard didn't have one either.
I wasn't into spending 500.00 plus dollars on a new one, and not really know if it was the ECU causing my problems. I could find no-one or nowhere here ( Ontario, Canada ) that would test the ECU. They just want to sell you a new one.
I found a place in Florida, ACE ( Auto Computer Exchange )
http://www.autocomputerexchange.com/Product/202 that tested the ECM and verified that it was toast. They charge $50 to test it. They can either rebuild yours or send you a warranted rebuild ( what I did ).
It saves you a lot of guessing and you'll know for sure if your ECU is toast.
Good luck
I figured it was the ECM. My local dealership didn't have another ECM I could try without buying it. The local wrecking yard didn't have one either.
I wasn't into spending 500.00 plus dollars on a new one, and not really know if it was the ECU causing my problems. I could find no-one or nowhere here ( Ontario, Canada ) that would test the ECU. They just want to sell you a new one.
I found a place in Florida, ACE ( Auto Computer Exchange )
http://www.autocomputerexchange.com/Product/202 that tested the ECM and verified that it was toast. They charge $50 to test it. They can either rebuild yours or send you a warranted rebuild ( what I did ).
It saves you a lot of guessing and you'll know for sure if your ECU is toast.
Good luck
#9
The did you ever figure out the reason the truck dies when you slam the doors, shut the hood, and hit potholes. If your ECM is mounted on the passengerside inner finderwell then you need to move it down an 1" or so. If you close the hood slowly and watch the ECM the hood hits it. After getting hit with the hood over and over when it is shut the hood snaps the plug on the ECM.