Which pins going to the ECU should be hot with the key on? - 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 Wrangler Forums > YJ Wrangler Technical Forum > Which pins going to the ECU should be hot with the key on?

Light up the holidays with LED lights from JeepHutIntroducing MONSTALINER™ UV Permanent DIY Roll On Bed LineRuffstuff Axle Simple Swap Kit!

Reply
Unread 09-01-2011, 05:37 PM   #1
AnonymousD
Registered User
1992 YJ Wrangler 
 
Join Date: Jul 2010
Location: Louisiana
Posts: 903
Which pins going to the ECU should be hot with the key on?

Im trying to track down the problem in my '92 4.0L. I tested all the pins and I get 12V on only the #3 pin. All the other pins are dead with the key on.

This is of course, with the computer out of the vehicle.

AnonymousD is offline   Reply With Quote Quick reply to this message
Unread 09-01-2011, 06:01 PM   #2
kloppk
Registered User
1992 YJ Wrangler 
 
Join Date: Oct 2006
Location: , Massachusetts
Posts: 2,721
Pin 9 should get 12 v from the ignition switch with the key in the Run position.

Pin 3 should have 12 v on it all the time regardless of the key position.
__________________
Baystate Jeepers
Deep Woods Extreme
New England 4 Wheelers
kloppk is offline   Reply With Quote Quick reply to this message
Unread 09-01-2011, 06:07 PM   #3
AnonymousD
Registered User
1992 YJ Wrangler 
 
Join Date: Jul 2010
Location: Louisiana
Posts: 903
Ok. So looks like it is probably my ignition switch then. Im getting 12V to pin 3 at all times, but nothing to pin 9 with the key on or off.

Sound about right?
AnonymousD is offline   Reply With Quote Quick reply to this message
Unread 09-01-2011, 06:12 PM   #4
oldtime_ironman
Web Wheeler
1991 YJ Wrangler 
 
Join Date: Dec 2010
Location: 14304 Niagara Falls, NY
Posts: 2,540
I think this link probably explains all of it. He has all that info in his write-up.

http://www.jeepforum.com/forum/f12/9...plained-490788

But yeah that would explain a lot about your ECU if only pin 3 is getting it.

.
oldtime_ironman is offline   Reply With Quote Quick reply to this message
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.
Note: All free e-mails have been banned due to mis-use. (Yahoo, Gmail, Hotmail, etc.)
Don't have a non-free e-mail address? Click here for a solution: Manual Account Creation
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.


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.