CEL light on, Diagnostic plug not working, where to start? - 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 Cherokee & Comanche Forums > XJ Cherokee Technical Forum > CEL light on, Diagnostic plug not working, where to start?

Trick Tabs - NalinMFG.comWarn, Smitybilt, Engo, Rugged Ridge Winches at CCORClayton Off Road XJ Long Arm Suspension Systems!

Reply
Unread 09-05-2011, 06:00 PM   #1
mithuth
Registered User
2003 TJ Wrangler 
 
Join Date: Aug 2006
Location: Warren, PA
Posts: 225
CEL light on, Diagnostic plug not working, where to start?

Quote:
My CEL light came on last night and when I went to Autozone to have the code checked, they couldn't get their machine to read. The guy said my OBDII plug is not connected to the computer or unhooked somehow. So I took it across the street to Advanced Auto and they plugged in their reader and it kept saying to plug it in. He said the same thing, "diagnostic plug is not connected to the computer." So I'm guessing I have to trace wires and find what's not plugged in. With an engine swap done recently, I'm guessing a plug was overlooked.
I'm not even sure where to start looking. I glanced under the dash, but didn't' see anything unplugged.
I did notice both of these while looking for things unplugged under the hood. What are they?

This I'm not sure what it is, but it has a "star" on one end and threaded above and below the nut on it.
I'm guessing it goes in the hole pictured below perhaps?


What goes here? (passenger side back of engine/front of tranny.)
Maybe the bolt from above?


__________________
-Jason
Build a man a Jeep, he wheels till it breaks,
Teach a man to build a Jeep, and he wheels for life.
mithuth is offline   Reply With Quote
Unread 09-05-2011, 06:29 PM   #2
tangofox007
Web Wheeler
 
Join Date: May 2005
Location: GA
Posts: 5,911
I would start by reinstalling that ground stud and then try reattaching the scanner.
tangofox007 is offline   Reply With Quote
Unread 09-05-2011, 07:23 PM   #3
cruiser54
Web Wheeler
 
cruiser54's Avatar
1990 MJ Comanche 
 
Join Date: Oct 2009
Location: Prescott, Arizona
Posts: 9,807
The stud with the nut on it attaches grounds to the engine dipstick tube.
Attach that before proceeding as Tango suggested.
cruiser54 is offline   Reply With Quote
Unread 09-06-2011, 10:50 AM   #4
mithuth
Registered User
2003 TJ Wrangler 
 
Join Date: Aug 2006
Location: Warren, PA
Posts: 225
The stud went into the block to hold the oil dip stick, as you guys said. The bolt the PO had in there goes to hold the auto fluid dipstick tube and tranny in the second pic. So all worked out there.

I haven't tried the diagnostics plug yet since fixing those, but I did notice a pretty severe antifreeze leak that I fixed. I'm gonna top off the antifreeze with some 50/50 mix and how that shuts the CEL off. If not, I'll make another stop at Autozone tomorrow morning.
__________________
-Jason
Build a man a Jeep, he wheels till it breaks,
Teach a man to build a Jeep, and he wheels for life.
mithuth is offline   Reply With Quote
Reply

Tags
cel , cherokee , code , OBDII , xj
Thread Tools


Suggested Threads





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.