Last night I parked my car, and tried to lock it using the remote. - didn't work.

Tried a couple of more times, got the 3 chirps indicating a problem with the system.
Got in the car, interior lights no longer come on.
Driver side button to release trunk lid no longer works.
This morning, noticed that when the car is idiling, the temperature guage now fluctuates from the bottom pin, to the current engine temp - but only when idiling, does it very quickly, like 5 - 6 times in about 20 seconds. When the temp guage hits the bottom pin, the check guages light flashes.

I checked the fuses, pulled the remote keyless entry fuse, and swapped it, no change, swapped the interior lights/radio fuse, no change - even though the radio still works fine.

This sound familiar to anyone?

Took it to a dealer.

This was apparently a hiccup in the BCM. (Body Control Module)
They re-programmed the BCM, and its working okay now.
Cost me $345 in labour for them to track the problem.
They can't tell me why it happened, other than maybe the BCM is failing. If it happens again, they told me I would have to replace the BCM ($600-800!!! + labour)

I had the same sort of problem with my 02 sunfire 2.2L eco - ends up it's a bad ground to the bcm, from what i hear it's a fairly common problem.

hope it helps...

i had a 2002 ecotec that had a dictionary of problems. ive even had my odometer read 'error' several times.