I own a 2007 Dodge Ram 2500 5.9L CTD w/ 3000 miles. I purchased it around the April time frame. On Friday, I towed a 6000 lbs. TT 400 miles through several Colorado mountain passes. There were absolutely no problems. In fact, I couldn't even tell that there was a TT behind me. On Saturday, I filled up and almost 30 minutes later, the check gage light turned on and remained on. Today, I towed the TT home (the light stayed on the entire time) and pointed out this check gage light to my father in law.

He asked if I filled up with fuel shortly before the light turned on. Sure enough, I remember filling up almost 12 miles before the light turned on. He told me to open the gas cap and close it again. The light went off after I did this. He didn't have an explanation for this but just told me that it has happened to him before. Anyone else ever hear of this? Why would my check gage light turn on after fueling and why would opening and closing the gas cap make it go away. *shrug*

 

vacume in the tank???

 

Thats what I thought, but when I opened the cap, it didn't seem as if air was rushing to get in or out.

 

Alot of the newer vehicles will throw a code if the fuel cap is not on or threaded properly. A couple of years ago I purchased a GMC Sierra and when I was test driving it. The engine light was on. The dealer told me that the gas cap was the wrong one because the original one fell off or something. They replaced it w/ the right one for my vehicle make. Cleared it and no engine light for the two years I owned it. I forget the reason they put a sensor on the fuel/gas cap. I wasn't really listening to the salesman.

 

Thats common with late model vehicles, but this is the first time I've heard about it on a diesel. It is a vaccum sensor I believe. Just make sure the cap clicks a few times when you screw it on.

 

Doesn't the sensor have something to do w/ the "people of california" knowning that vapor's from a fuel tank are bad for you?

 

happend to me on my '02 ram 1500..same problem not putting the cap on all the way...just dissconnected and reconnected the electircal power from the battery and everything was good to go

 

Anything is possible out here.[sm=boohoo.gif]