5.9 pcm - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Grand Cherokee & Commander Forums > ZJ Grand Cherokee Forum > 5.9 pcm

Rough Country Lift Kits and Parts!The ULTIMATE "Selectable" Locker System! BroughIntroducing MONSTALINER™ UV Permanent DIY Roll On Bed Line

Reply
Unread 02-01-2013, 05:42 PM   #1
MN59ZJ
Registered User
1998 ZJ 
 
Join Date: Apr 2010
Location: Lakeville, MN
Posts: 557
5.9 pcm

I'm having an issue that may be caused the PCM in my 5.9 ZJ. I'm simply wondering if I can yank the PCM from a 5.9 Durango or Dodge pickup at the u-pull lot & swap it into the ZJ to see if that solves my problem?

MN59ZJ is offline   Reply With Quote
Unread 02-01-2013, 05:48 PM   #2
T-nave
Registered User
1998 ZJ 
 
Join Date: Jan 2012
Location: Grand Ledge, MI
Posts: 205
I could be wrong on this but I believe the 5.9 is programmed differently. It may work but your not going to get the same performance. Now would be a good time to get a custom tuned pcm. The person that programs it may be able to check/fix problems with yours.
__________________
9er, 3.5 IRO lift + 3/4" spacers w/ adjustable trac bars and arms, 242 swap, 285/70/17 Duratracs and some other doo dads
T-nave is offline   Reply With Quote
Unread 02-01-2013, 06:01 PM   #3
MN59ZJ
Registered User
1998 ZJ 
 
Join Date: Apr 2010
Location: Lakeville, MN
Posts: 557
Quote:
Originally Posted by T-nave
I could be wrong on this but I believe the 5.9 is programmed differently. It may work but your not going to get the same performance. Now would be a good time to get a custom tuned pcm. The person that programs it may be able to check/fix problems with yours.
It's a LONG story, but I have an SCT tuner & a recently rebuilt (& improved ;-) ) engine. The problem I'm having is likely either caused by a bad PCM, or an error with the tuner. As I've chased every other possibility down with no success. For now, I just want to pop in another PCM & see if the issue goes away.
MN59ZJ is offline   Reply With Quote
Unread 02-01-2013, 06:20 PM   #4
T-nave
Registered User
1998 ZJ 
 
Join Date: Jan 2012
Location: Grand Ledge, MI
Posts: 205
Cant you default back to original settings of your pcm? Then unhook your tuner?
__________________
9er, 3.5 IRO lift + 3/4" spacers w/ adjustable trac bars and arms, 242 swap, 285/70/17 Duratracs and some other doo dads
T-nave is offline   Reply With Quote
Unread 02-01-2013, 06:28 PM   #5
MN59ZJ
Registered User
1998 ZJ 
 
Join Date: Apr 2010
Location: Lakeville, MN
Posts: 557
Quote:
Originally Posted by T-nave
Cant you default back to original settings of your pcm? Then unhook your tuner?
I have. The code pops up in stock mode too, which indicates the PCM, but the problem didn't occur until I started using the tuner, which seems odd, but might be a coincidence. I can get a Dodge 5.9 PCM for $18. so if I can throw that in & see what happens, I can either confirm or eliminate the PCM as the problem & go from there... That is if the Dodge unit will work for this purpose.
MN59ZJ is offline   Reply With Quote
Unread 02-01-2013, 08:04 PM   #6
newfieZJ
Registered User
1995 ZJ 
 
Join Date: May 2008
Location: , Alberta
Posts: 6,391
For 18 bucks , no harm trying . What code ?
newfieZJ is offline   Reply With Quote
Unread 02-01-2013, 08:24 PM   #7
MN59ZJ
Registered User
1998 ZJ 
 
Join Date: Apr 2010
Location: Lakeville, MN
Posts: 557
Quote:
Originally Posted by newfieZJ
For 18 bucks , no harm trying . What code ?
Depends. The SCT. Has a built-in reader & gives P0140, but the Eqquis at O'Reilly's gives P0172. They are actually similar results, involving O2 sensors detecting a rich mix. Once I reset it, it runs fine on the next start up, I could drive til the tank is empty & it won't pop a code. But once I shut down, the next time I start it up, I get the code after 3-4 minutes, then it runs rich until I reset it.

It gets more complicated than that, but That's it in a nut shell.
MN59ZJ is offline   Reply With Quote




Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.