How can I tell if my ECU is shot? - JeepForum.com

Reply
 
LinkBack Thread Tools
post #1 of 37 Old 03-28-2010, 02:30 PM Thread Starter
lexinator02
Registered User
1995 YJ Wrangler 
 
Join Date: Sep 2009
Location: waukesha
Posts: 126
How can I tell if my ECU is shot? SHE STARTED!!!

I have a 90 yj with a 2.5L and a 5 speed and I am pretty sure my ECU is shot. Is there any ways I can use a mulitmeter to see if it is shot or do I just have to bite the bullet and buy a new one to see?

Dave


Low Output 4 Cylinder Jeep Club Member # 187
1995 YJ

Last edited by lexinator02; 03-31-2010 at 05:22 PM.
lexinator02 is offline  
Sponsored Links
Advertisement
 
post #2 of 37 Old 03-28-2010, 05:35 PM
laybackman
Bikini Bridge Inspector
 
laybackman's Avatar
2010 JK Wrangler 
 
Join Date: Dec 2002
Location: Massachusetts
Posts: 6,977
Quote:
Originally Posted by lexinator02 View Post
I have a 90 yj with a 2.5L and a 5 speed and I am pretty sure my ECU is shot. Is there any ways I can use a mulitmeter to see if it is shot or do I just have to bite the bullet and buy a new one to see?

Dave
When you turn your ignition to the ON (not START) position and your various dash gauges light, up does your CEL come on also? If it does it is probably OK.

Do you know what was good about the good old days? I wasn't good, And I wasn't old!

Senators and Congressman should wear uniforms like NASCAR drivers so we could identify their corporate sponsors....
laybackman is offline  
post #3 of 37 Old 03-28-2010, 05:57 PM
Que89YJ
Web Wheeler
1989 YJ Wrangler 
 
Join Date: Apr 2008
Location: Detroit
Posts: 22,863
Its a 1990 so it predates the SMEC or the SBEC so the CEL light isnt a good indicator. I guess the better question is why do you think the Engine controller is bad? Whats wrong with your jeep?
Que89YJ is offline  
post #4 of 37 Old 03-28-2010, 07:20 PM
laybackman
Bikini Bridge Inspector
 
laybackman's Avatar
2010 JK Wrangler 
 
Join Date: Dec 2002
Location: Massachusetts
Posts: 6,977
Quote:
Originally Posted by Que89YJ View Post
Its a 1990 so it predates the SMEC or the SBEC so the CEL light isnt a good indicator. I guess the better question is why do you think the Engine controller is bad? Whats wrong with your jeep?
Since it was a 2.5 I thought it was since it has TB injection. But you are right that all started in '91 didn't it? But the good question is what you asked the OP..why do you think it needs to be replaced?

Do you know what was good about the good old days? I wasn't good, And I wasn't old!

Senators and Congressman should wear uniforms like NASCAR drivers so we could identify their corporate sponsors....
laybackman is offline  
post #5 of 37 Old 03-29-2010, 07:03 AM Thread Starter
lexinator02
Registered User
1995 YJ Wrangler 
 
Join Date: Sep 2009
Location: waukesha
Posts: 126
http://www.jeepforum.com/forum/f12/a...st-lol-991642/

I have this thread going I just wanted an individual question about the ECU. I would love an answer like take a multimeter at all these plugs on the ecu harness and you should get this value. That way I would know if the inputs and outputs are normal.

Dave

Low Output 4 Cylinder Jeep Club Member # 187
1995 YJ
lexinator02 is offline  
post #6 of 37 Old 03-29-2010, 12:13 PM
laybackman
Bikini Bridge Inspector
 
laybackman's Avatar
2010 JK Wrangler 
 
Join Date: Dec 2002
Location: Massachusetts
Posts: 6,977
Quote:
Originally Posted by lexinator02 View Post
http://www.jeepforum.com/forum/f12/a...st-lol-991642/

I have this thread going I just wanted an individual question about the ECU. I would love an answer like take a multimeter at all these plugs on the ecu harness and you should get this value. That way I would know if the inputs and outputs are normal.

Dave
You would need to know the electrical values of all the pinouts on the brain whether they be input OR out put voltages. A FSM is the best place for that information.

Do you know what was good about the good old days? I wasn't good, And I wasn't old!

Senators and Congressman should wear uniforms like NASCAR drivers so we could identify their corporate sponsors....
laybackman is offline  
post #7 of 37 Old 03-29-2010, 12:21 PM Thread Starter
lexinator02
Registered User
1995 YJ Wrangler 
 
Join Date: Sep 2009
Location: waukesha
Posts: 126
well for the heck of it I decided to open up the ECU and check it out. I found a capacitor/resister completely burnt and cracked and the backside of the board was burnt in that spot as well so I think its safe to say my ECU is shot lol

Dave

Low Output 4 Cylinder Jeep Club Member # 187
1995 YJ
lexinator02 is offline  
post #8 of 37 Old 03-29-2010, 03:24 PM
laybackman
Bikini Bridge Inspector
 
laybackman's Avatar
2010 JK Wrangler 
 
Join Date: Dec 2002
Location: Massachusetts
Posts: 6,977
Quote:
Originally Posted by lexinator02 View Post
well for the heck of it I decided to open up the ECU and check it out. I found a capacitor/resister completely burnt and cracked and the backside of the board was burnt in that spot as well so I think its safe to say my ECU is shot lol

Dave
This link goes to one of several fixes for bad capacitors in a brain;
http://www.jeepforum.com/forum/f12/c...rs-ecu-492597/

Do you know what was good about the good old days? I wasn't good, And I wasn't old!

Senators and Congressman should wear uniforms like NASCAR drivers so we could identify their corporate sponsors....
laybackman is offline  
post #9 of 37 Old 03-29-2010, 04:03 PM
Que89YJ
Web Wheeler
1989 YJ Wrangler 
 
Join Date: Apr 2008
Location: Detroit
Posts: 22,863
He has the renix controller on the Renix controller on the inside of the vehicle. Its the first time I heard of this happening. Pics would be appreciated. I agree though. It should be similar in the issues as the Sbec and it should be repairable. The cao should be on the input pin for power and should be easily replaced. A resistor would be a new one for me too.
Que89YJ is offline  
post #10 of 37 Old 03-29-2010, 04:13 PM Thread Starter
lexinator02
Registered User
1995 YJ Wrangler 
 
Join Date: Sep 2009
Location: waukesha
Posts: 126
Here are some pics of what I found. I could not tell if it was a resistor or capacitor...










Dave

Low Output 4 Cylinder Jeep Club Member # 187
1995 YJ
lexinator02 is offline  
post #11 of 37 Old 03-29-2010, 04:39 PM
laybackman
Bikini Bridge Inspector
 
laybackman's Avatar
2010 JK Wrangler 
 
Join Date: Dec 2002
Location: Massachusetts
Posts: 6,977
Quote:
Originally Posted by lexinator02 View Post
Here are some pics of what I found. I could not tell if it was a resistor or capacitor...










Dave
I think it is a big resistor. What you need to know is what was it's value. Can you see the stripes on it? That gives you the value.

Resistor Color Code Table And Calculator

Do you know what was good about the good old days? I wasn't good, And I wasn't old!

Senators and Congressman should wear uniforms like NASCAR drivers so we could identify their corporate sponsors....
laybackman is offline  
post #12 of 37 Old 03-29-2010, 05:15 PM Thread Starter
lexinator02
Registered User
1995 YJ Wrangler 
 
Join Date: Sep 2009
Location: waukesha
Posts: 126
no its solid black from being burnt. It does look a lot like the resistor in the 2nd pic though...

Low Output 4 Cylinder Jeep Club Member # 187
1995 YJ
lexinator02 is offline  
post #13 of 37 Old 03-29-2010, 05:26 PM
wrangler76
Registered User
1995 YJ Wrangler 
 
Join Date: Sep 2009
Location: Carson, WA
Posts: 412
Does the "R125" on the board specify anything useful?
wrangler76 is offline  
post #14 of 37 Old 03-29-2010, 05:32 PM
JOExFROMxNY
Registered User
1988 YJ Wrangler 
 
Join Date: Dec 2009
Location: Long Island, NY
Posts: 744
Quote:
Originally Posted by wrangler76 View Post
Does the "R125" on the board specify anything useful?
R=resistor
D=diode
C=capacitor

Look for a number underneath it. That "R" might be for the resistor next to it.
JOExFROMxNY is offline  
post #15 of 37 Old 03-29-2010, 05:33 PM
laybackman
Bikini Bridge Inspector
 
laybackman's Avatar
2010 JK Wrangler 
 
Join Date: Dec 2002
Location: Massachusetts
Posts: 6,977
Quote:
Originally Posted by lexinator02 View Post
no its solid black from being burnt. It does look a lot like the resistor in the 2nd pic though...
That was my thought also it does look quite similar. I wouuld look inder the burntt one also and see if you can see any hint of the stripe(s) on it OR find one that is the same size and see what it's value is. Then buy one and swap out the bad one for the new one....What have you got to lose at this point?

Do you know what was good about the good old days? I wasn't good, And I wasn't old!

Senators and Congressman should wear uniforms like NASCAR drivers so we could identify their corporate sponsors....
laybackman is offline  
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.



Email Address:
OR

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.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Jeep Forums Replies Last Post
Are my springs shot? GilpinTJ TJ Wrangler Technical Forum 4 06-14-2009 12:25 PM
Shot BJs AROSETO TJ Wrangler Technical Forum 4 10-23-2008 07:25 PM
my new JK shot by a BB Gun! etownjay8 JK Wrangler Technical Forum 31 09-26-2007 03:35 PM
a long shot but mudluva TJ Wrangler Technical Forum 2 01-07-2007 07:43 PM
D35 shot? prossett YJ Wrangler Technical Forum 5 09-26-2005 02:29 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome