I would recommend cruising eBay to see what you can find.
I had the same problem. Google "keyless entry remote 2003 Jeep Grand Cherokee".
replace the remote
The obvious answer is the one the Jeep sells at its dealerships parts department.
Possible weak battery in the remote.
No, remote start was not a factory option in 2000.
I found a remote for my 1997 Grand Cherokee on Ebay. type in the number "05014736". The remote if for the newer generation Grand Cherokee, but I took it to the dealer, and they programmed it for free.
You disarm the security by unlocking the doors with a key or remote.
Check Google.com
centre top dashboard (red dome)
You have to program it with a DRB (Scan tool).
Advance auto and Carquest auto parts.
A 1991 Jeep Cherokee computer is what fits a 1991 Jeep Cherokee.