Bypass module instal on 03 impala installed Gmdlbp nothing there was something mentioned about a flash

It sounds like the bypass module, or the key that you have in a universal bypass box is not programmed. When remote starting the vehicle check to see if the yellow key light starts flashing on. That would confirm my prognosis.

You can also remove the a/c compressor and install a bypass pulley in its place. You can still use the standard belt this way, just run it to the bypass pulley instead of the a/c compressor. RockAuto has them at the link.
http://www.rockauto.com/en/catalog/chevrolet,2001,impala,3.8l+v6,1384084,heat+&+air+conditioning,a/c+compressor+bypass+pulley,10329

your local radio installation shop should have a bypass module

Has this unit operated correctly before? Or is this something that was recently installed and this is the result of the installation? What it sounds like to me is that the Python Unit and the car's own security system are conflicting with each other. Most aftermarket car starter/entry/alarms systems require a "bypass module" be installed to disable the factory alarm system while the aftermarket unit is doing its thing (as there is no key in the ignition). If this is a new install the module may not have been installed or may have been installed incorrectly. If this is something that has worked and is now acting up, the bypass module may be malfunctioning.

I had the same issue with my 2001.. I did some research and found this module that will bypass it and u can even install it yourself so no garage fee's .!!! check it out and see if u think it will work for u . hope this helps ya

Is this a crank no start issue ? If so, is the theft light in the cluster flashing ? No mention about the PATS bypass. One try is to put a functioning key in the ign ( in the off position is fine ) and try to remote start the truck. This would satisfy the PATS check, to know if the PATS bypass is programmed correctly, or if you do not have one, if everything else is installed correctly and you just need to add a PATS bypass module.

You need to buy the fittings first they are sold by a company called HELP motormite. Very common to go bad. You will need to buy or borrow springlock tool. Are sold seperately or in a set. What they are is a garter spring that will disconnect quick connector on fittings. The parts store will have them too.

Try under the dash, attached to colum is a switch that the rod goes into from your ignition key switch, that may need to be adjusted tword your steering wheel just a touch, they go out of alignmnet from time to time

there might be a "FRITZ" in the computer setting off different alerts in the car at times.. have you taken it to a dealer yet?

I don't know anything about a bypass module? Maybe the manufacturer can walk you through your problems? Otherwise
Make sure battery has a full charge. With original wiring, try the 30 minute relearn procedure. Any applicable trouble codes? You may need a scanner that can communicate with your security system?