I have a 99 GMC Sierra. 5.3,Auto.   I have an compustart remote start system
and keyless entry.  Remote start and remote entry works fine however
sporadically the factory security system turns itself on and will not allow
the truck to start.  turns over put no fuel pump(I assume since it acts like
no gas).  After I attempt to start it, the security light flashes 5 times
and then nothing in the message center.  After several attempts at cycling
the ignition, it will restart and all is good for a while.  I did scan for
codes and no codes came up.  I've tried locking everything up and unlocking
with the key instead of the remote but doesn't seem to help.  Anyone else
have this issue before?  Any ideas on how to fix this so I don't get
stranded somewhere with a truck that won't start?  Thanks in Advance.