CEL flashes 12 times with the key on...

[Liberty02sport]

Did a search but didn't come up with much.. The '02 is running like a old harley motorcycle and when a buddy and I checked for stored codes there were non but when you turn the key to the "ON" position after a few seconds the check engine light flashes 12 time then stays on.

The engine is NOT running when the CEL flashes 12 times, it just happens when the key is on. The computer is NOT storing any codes. The Jeep is running like absolute crap and no CEL or stored codes when the engine tries to run. Thanks guys...

 

[Bulli]

Did you check for any misfire, dead plug or dead injector? Coolant loss without a leak?
I assume it is the 3.7?

 

[Liberty02sport]

Don't have any of the tools needed to check the injectors, and it isn't throwing any misfire codes that could be found. Coolant level looked normal.Yep, it's a 3.7

 

[Doublecardan]

Since you already tried to check the CEL for codes, the next step is to plug in a proper scan tool and check the datastream and see if anything comes up, Because you have a CEL that stays on there should be a code generated. It is possible that you have an ecm problem if nothing is shown on the scantool, that would be a pointer in the right directon.Good luck with it

 

[Liberty02sport]

Since you already tried to check the CEL for codes, the next step is to plug in a proper scan tool and check the datastream and see if anything comes up, Because you have a CEL that stays on there should be a code generated. It is possible that you have an ecm problem if nothing is shown on the scantool, that would be a pointer in the right directon.Good luck with it

When we checked the codes my buddy was using an $1800 scan tool that he uses at his shop. It still didn't pull any codes up. Is there some jeep specific scan tool that should be used to check it ?? Obviously there's something wrong with it but it doesn't want to cooperate with giving us the slightest clue as to where to begin to look.

 

[Doublecardan]

Sorry I did not respond sooner, WHile Chrysler does have a specific scantool, it is not needed to Diagnose alot of the problems with Engine, Chrysler in fact is one of the most generous for scantool makers in providing the bidirectional tests at least up until 2005 when they changed to a different electronic system. Jeeps are chryslers when it comes to electronics, now you have used a scantool to check codes, I really said to check the datastream because if you dont have codes then the datastream is the next best thing, but you are not getting that, so you have a communication problem with your ecm, that in itself is a good pointer and can be traced using a FSM.