1984-1990 w/AMC engine are pre-OBD.

1984-1986 w/GM V6-173 are OBD-I (GM control setup.)

1991-1995 are OBD-I (Chrysler)

1996-2001 are OBD-II (Chrysler)

The "Key Tricks"
Older (OBDI) models - Start with the ignition off. Within five seconds, switch the key on, off, on, off, on. ("On" is NOT "Start" and "Off" is NOT "Lock"). The "check engine" light will flash. Count the flashes. Each code is a two digit code, so a (for example) 23 would be FLASH FLASH (pause) FLASH FLASH FLASH (long pause). It will never flash more than 9 times, so watch for those pauses!

Newer (OBDII) models - Put the key into the ignition, push down the odometer reset button, then turn the key to RUN with your finger on the button - and then release the button. The odometer will go through 1111111 through 999999, then display the car's serial number. It will then show the error codes (it might show them starting with P). If this method does not work, try the OBDI method.

 

So I did that and the jeep went through the self diagnostic cycle and NO CODES APPEARED!!! Im so damn confused...

 

I don't see how any code could be read via the cluster self diagnostic, that's why we have OBD2 scan tools. Disconnecting the battery, waving a magic wand, or dancing the jig in your girlfriends underwear won't erase flash memory either. The only reason the light did not come on right away is it's not a hard fault.

 

Im just extremely confused as to how the Check Eng Light is on, but when a code reader is used it says "No Codes Found".....????? It makes no damn sense to me...

 

You had apparently (2) stored codes when read @ autozone, you repaired the faults.


Those previous (2) codes though still stored (not erased) are no longer valid "No codes found".


Hope this makes sense, until the prior codes are properly erased the light will be on.

 

That makes sense, but th A-Z guys said they could not delete any codes if it shows "No Codes FounD"... I'll take it back and have someone different do it...

 

The A-Z guys cannot erase codes they can only check for the codes. You really need to go to a MECHANIC with a scan tool to have him or her (i'm not a sexist) clear the code for you. That is the best option (really the only choice) you have.

 

Actually... The A-Z guys can erase codes, only problem is once the vehicle goes thru a couple times being driven the computer finds the error again...

 

This is an incredibly stupid question, but I just have to ask...

Are you sure it's your check engine light, and not the maintenance required light? CEL would be for when codes come up, and MAINT should come on after however many miles, telling you you to get a tune up and stuff.

Had to ask.

 

Smart question to ask. Being a mechanic I've seen it sooooooooooooooooooooooooooooooo.....much. Take a pic of said light and post it on here.

 

Yes.... Its the light that says "Check Engine". Im not that dumb...

 

Hey, he was just trying to help. He doesn't know what your level of car experience might be. Or lack thereof.