After changing alternator Check engine light is on -
LinkBack Thread Tools
post #1 of 6 Old 03-23-2019, 02:25 PM Thread Starter
Registered User
bman21's Avatar
1997 TJ Wrangler 
Join Date: Apr 2015
Location: STM
Posts: 57
After changing alternator Check engine light is on

I Got a 1997 TJ 2.5. 5 speed. I Just changed the alternator because the old one was seized up. After changing the alternator now the check engine light is on and the codes it giving is 37 and 25. Any help I’d really appreciate it. It did not have the CEL on before I began. All the gauges bounce to very irractic. I know this are the code but not sure where to begin and if it has anything to do with changing the alternator. 25** A shorted or open condition detected in one or more of the idle air control motor circuits. Actual idle speed does not equal target idle speed.37** Relationship between engine speed and vehicle speed indicates no torque converter clutch engagement. An open or shorted condition detected in the torque converter part throttle unlock solenoid control circuit. Incorrect input state detected for the Park/Neutral switch. Auto only.

bman21 is offline  
Sponsored Links
post #2 of 6 Old 03-23-2019, 02:48 PM
Real Jeeps have dents
CJ7-Tim's Avatar
2000 XJ Cherokee 
Join Date: Apr 2002
Location: out in the garage - Minneapolis
Posts: 28,281
Is the battery almost or fully charged ?

Confirm all the wire connections are snug, and are connected correctly. Test the alternator output at the alternator and at the battery.

About 10 -15% of cheap crappy rebuilt in China alternators are defective, the ones that come with a "Lifetime Warranty" are the biggest offenders. Did you have the parts store test the alternator before you paid for it ?

“When the people find that they can vote themselves money, that will herald the end of the Republic.”

- Benjamin Franklin
CJ7-Tim is offline  
post #3 of 6 Old 03-23-2019, 02:54 PM
Web Wheeler
dbbd1's Avatar
2006 TJ Wrangler 
Join Date: Aug 2008
Location: Oregon
Posts: 1,008
Your problems could be due to low voltage because the new alternator is not charging the battery. Like above, double check your connections. If you still have problems, yes, you may need to get the new one tested. What is your battery voltage, as measured at the battery with a voltmeter?

The opinions of worthless people, are worthless.

The only problem that you have with anyone in this world, is what you expect of them.

Society is no match for a stupid person.

"Life Is tough but it is tougher when you are stupid"

-John Wayne
dbbd1 is offline  
post #4 of 6 Old 03-23-2019, 04:07 PM
Web Wheeler
jtec's Avatar
2014 JK Wrangler 
Join Date: Oct 2017
Posts: 8,295
I am confused - likely the bourbon,
BUT why do we have 2 digit codes on a OBDII 1997

When I see the price of OEM I think aftermarket.
When I see the quality of aftermarket I think OEM.
jtec is offline  
post #5 of 6 Old 03-24-2019, 07:25 AM
Senior Member
williambmac's Avatar
2005 LJ Wrangler 
Join Date: Aug 2007
Location: Roxbury, N.J.
Posts: 717
Originally Posted by jtec View Post
I am confused - likely the bourbon,
BUT why do we have 2 digit codes on a OBDII 1997

Key on/off 3x method, flashes out codes on the ipc.

2005 Rubicon Unlimited, 4" Clayton long arm
35" Mickey Thompsons, lots of stuff
Black Magic Big brake kit
williambmac is offline  
post #6 of 6 Old 03-24-2019, 04:15 PM Thread Starter
Registered User
bman21's Avatar
1997 TJ Wrangler 
Join Date: Apr 2015
Location: STM
Posts: 57
So after further investigation I took the alternator back off and when doing so I noticed that one of the terminals wasn’t tight and wouldn’t tighten up. So I removed the nut that was behind it and it allowed me to tighten the terminal up where it needed to be. I also cleaned all terminals and charged the battery all the way up just to make sure that wasn’t the problem. Sure enough no check engine light and no codes!! Back to jeepin!
bman21 is offline  

Quick Reply

Register Now

In order to be able to post messages on the forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.

Email Address:


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
My goal is to get 25+ mpg from my 99 XJ with 30 x 9.5 R15 ATs Charley3 XJ Cherokee Technical Forum 3864 10-19-2019 10:58 PM
12 Things You Can Do When Your ZJ Stalls ZeeJay1997 ZJ Grand Cherokee Forum 448 05-28-2019 07:14 PM
check engine light on and gasscap warning NS_Jeep Jeep MK Compass & Patriot Forum 2 10-12-2018 02:54 PM
Check Engine Light help nateb66_ WK Grand Cherokee & XK Commander Forum 0 07-13-2018 05:22 PM
2009 Jeep Liberty new (to me) engine problem NancyLou KK Liberty Forum 4 03-09-2018 04:22 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