I have a 2006 town and country. On the mileage display where the odometer reading should be it says gascap. What is causing that display to have a read out like that? And what can i do to fix it?

Replace the Gas Cap.

The message usually means the engine has been run with the gas cap off, or the cap is leaking.
You may have to use a scanner or code reader to erase the code.
Check your owners manual for details.

When you fill up make sure that the car engine is stopped and keys are out of ignition, only stopping the engine but leaving the contact on or on accessories position will interfere with the car computer calculating the mileage base on the amount of fuel you pump.

The "gascap" warning tells you that there is a leak somewhere in the fuel tank, fill neck, or gas cap that is preventing vacuum from developing in the tank. If you are certain that your gas cap is good, the second most likely culprit is the fuel fill neck gasket was compromised during the accident, or that there was unnoticed damage to the gas tank which is not allowing a vacuum to develop inside the tank.

I assume it is displaying gas cap on the odometer. This happens when the van sees a EVAP leak. It is small and is telling you to make sure the gas cap is tight. If it is you probably have a leak in the EVAP system. If it gets worse it will turn on the check engine light.

The most likely reason your display is reading gas cap is that you have an unsolved evaporation code. Most of the time simply replacing the gas cap will fix the problem, but since you have already done that there is a whole list of other things you could check. I would start with your hose that runs to your tank from your fill spout. It is possible that it has a small crack in it. Or it is even possible that one of your injector O rings has gotten bad. The bottom line is that evaporation codes are very hard to pin point and usually do not cause any problems at all. So if you decide to do nothing and not spend any money on the problem you will probably be just as well off. Well that is other then being annoyed by your gas cap light. I hope this helps you out, and if you have any other questions please feel free to ask.

You may have a faulty gas cap. If you are tightening the cap down securely the light will go off after the car is driven about 40 miles. I suggest installing a new gas cap which should cost about $15 at your local auto parts store. *** Please rate me on this answer.***

I get many calls a week for this procedure...
This is really easy! Follow these directions:

Turn the key ON

Look at the odometer, and verify that it displays "ODO" and the total mileage traveled. If it is on "Trip A" or "Trip B", press the black stick next to the odometer to read "ODO", and the total miles traveled.

Turn the key OFF.

Press in, and HOLD the black trip meter reset button, hold it in.
DO not release it.

Turn the key ON

Observe the Odometer display. The total mileage traveled will disappear, and you will see 5 dashes, then 4, then 3, then 2, then 1 dash, and finally, 5 zeros. Then, the total mileage traveled will redisplay.

Release the black trip meter reset stick.

This completes the reset procedure, and it will be back on in 5,000 miles, to remind you of you next oil change.

Hope this helps!

check the o-ring under the cap or just replace cap,dodge uses a system called leak detection with a small pump to put vacumm on the evap system if the system fails to hold vaccum then it is 90% time the fuel cap or bad vaccum line in evap system or purge valve.

I get many calls a week for this procedure...
This is really easy! Follow these directions:

Turn the key ON

Look at the odometer, and verify that it displays "ODO" and the total mileage traveled. If it is on "Trip A" or "Trip B", press the black stick next to the odometer to read "ODO", and the total miles traveled.

Turn the key OFF.

Press in, and HOLD the black trip meter reset button, hold it in.
DO not release it.

Turn the key ON, do not start the engine

Observe the Odometer display. The total mileage traveled will disappear, and you will see 5 dashes, then 4, then 3, then 2, then 1 dash, and finally, 5 zeros. Then, the total mileage traveled will redisplay.

Release the black trip meter reset stick.

This completes the reset procedure, and it will be back on in 5,000 miles, to remind you of you next oil change.

Hope this helps!