2000 Jeep Wrangler check engine light

I have a 2000 Jeep Wrangler with a 4.0l motor. When the temperature is < ~45 degrees and I have the heater or window defroster on, the check engine light comes on.



When the temperature is not cold, the light never comes on.



Thank you in advance for your help.



Clarke

GO TO AUTOZONE AND GET THE CODE PULLED.ITS FREE AND JUST TAKES A FEW MINUTES BY PLUGGINGV A READER UNDER THE DASH.IT WILL TELL YOU WHAT SENSOR OR SECTION TO START CHECKING.IVE NEVER HEARD OF THE WIPERS HAVING ANYTHING TO DO WITH THE CHECK ENGINE LIGHT.ANYWAY MY GUESS IS THE COOLANT TEMP SENSOR MAYBE.CHECL ALL SENSOR CONNECTOR FOR BENT PINS,LOOSE CONNECTORS,AND BAD WIRES.

Thank you! I read on a website that I could tell what code was turning it on by turning the key a couple of times, but found out that the 2000 TJs have a newer computer and the only way to find out what code is tripped is by using a reader. I will go have it checked and see what is says. I have had my Jeep inspected and they tested the emissions, so I am hoping that it isn’t a cat problem. I would think that the emissions test would have been a problem if the cat is going bad. Clarke

That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code (like P0123) not just their translation into English and post it back here.