Toyota Repair: Gag gauge, cluster, or fuel level meter repair for 02 Celica GT, auto. trans., toyota celica gt, gas gauge

Question
Dear Sir,
         I would like to know if you know any answers of what the
problem might be.
         The car that I have is a 2002 Toyota Celica GT and is an
automatic transmission. The mileage that I have on the car is about 55K.
         The problem that I have is with the electronic gas gauge. It
has to do with the gas gauge, cluster, or fuel level meter as what I
suppose on the situation. What happens is that there are bars that shows
the level for the gas to be shown as being full to empty. I've noticed
that only one of all the bars goes down as if it will be empty later on
,but when I fill the tank back up it goes back to normal. Sometimes it
will take a few minutes to let it go up or if I drive the car at a
later time. The problem is when the level meter goes down, only one bar
goes and not the rest. The whole time, it sits there at only one bar down.
The gas tank indicator doesn't turn the light on when it is about to be
empty. There isn't any problems when I fill up the tank.
         Now I keep track of the miles, the maximum that I run would
be around 330 which is alittle risky although I always fill the tank
back up at 200 miles. A couple more that I noticed while I was driving is
that the doors automatically locks when either I go past 30 miles per
hour or just only locks when I start the car up. I also see that when I
make a sharp turn, the doors automatically unlocks.
              Hopefully I gave you enough information to find out what
the problems are about to be. Thank you for your time and effort. Let
me know what the issues are and if you don't mind sending your
explainations to my email address as well. Again, thank you very much and I appreciate it.

Answer
I dont have your email address.

I would suspect a bad fuel sender inthe tank.
You can take out the back seat and remove plate in the floor and take out the sender.
Manually move the lever up and down and see if the gauge changes.if nothing then its probably the sender.
I havent seen a bad gauge yet.

You may have a bad door switch or a door that isnt shutting correctly.
Does the dome light flicker when the locks operate?

You can get wiring and repair diagrams at www.techinfo.toyota.com

Mike