I drove to work yesterday morning - nothing out of the ordinary.

When I left in the afternoon, however, I noticed that on the drive
home, the Impala (2001) was acting VERY strangely.....

Doors would lock...then unlock...trunk would unlock..."Security" would
display..."Service Vehicle Soon" would display...the "Battery" icon
would display...interior lamps would flicker on and off...and the air
conditioner would eminate hot air.  All of the aforementioned would
repeat over and over the entire trip home.

Because of the nature of some of the above actions, I suspected maybe
there is a malfunction with the remote keyless entry device.

Upon return home, I removed that device and with ONLY the key in my
possession in the vicinity of the car, I started it.  All was normal.
No warnings, no bells, no flickering, and even ice cold air from the
air conditioner.

To see if I could reproduce the situation, I then retrieved the keyless
entry device from the house and brought it to the car, started it, and
the strange behavior returned.  I then reproduced the scenario with
only the key, and all returned to normal.  I then figured that I simply
had to discard the faulty keyless entry device.

This morning, I worked from home, and my son took the car to work.
Upon his return home, he mentioned that the car was acting very strange
(same activities described above).  I then informed him that he must
have used the wrong set of keys since the one keyless entry device was
faulty.

I then used the car later...using ONLY the key...I did not have any
keyless entry devices in the area...but the car acted very strangely
again.  It seems NOW that perhaps it is NOT the keyless entry device
but something within the vehicle.  Even when I turned the car off, the
strange locking/unlocking behavior would continue.

I finally disconnected the battery for a short while, then re-connected
it.  The strange behavior stopped.  But, once I re-started the
ignition, everything resumed (flickering, bells, warnings).

My question is whether anyone had experienced such strange behavior by
their vehicle and whether you know of any cause and/or resolution.

Thanks.

Richard