Instructions for a 1999 Cadillac Escalade Keyless Entry Remote Fob
Verify that this important information is on the back of your remote before using these programming instructions.
FCC ID: AB01502T, ABO1502T
Factory Part No: 16245100-29, 16245104, 16207901-5
Programming Notes:
Obtain all remote transmitters for this vehicle. This procedure will erase all previously programmed remotes. You must program all existing and new remotes that you wish to use on the vehicle at this time.
Keyless Entry System Memory Clearing Instructions are noted in the dark blue colored steps below.
Step-by-Step How To Programming Instructions:
Be sure ignition is OFF.
Remove RADIO fuse from fuse box. The RADIO fuse will be Number 17 and located at left-hand (LH) driver’s side of the instrument panel.
Turn ignition from OFF to RUN 3 times within 5 seconds ending in the RUN position. OFF is the position where you can remove your key and RUN is the position just shy of starting your vehicle (do not crank engine or start vehicle during programming).
Doors will Lock and Unlock indicating successful entry into programming mode.
Hold Lock and Unlock at the same time on first remote for approximately 15 seconds. Vehicle will respond by locking and unlocking doors indicating successful programming.
Repeat Step 5 for each additional remote to be programmed.
Switch ignition OFF. Replace RADIO fuse.
Test all remotes. Programming is now complete.
 
IMPORTANT: Before entering programming mode, have in possession all of the transmitters you will be using on the vehicle. Once you program the transmitter, all previous codes will be erased from the memory. The other transmitters will not be functional until you program the transmitters again.
1. Locate the Data Line Connector (DLC) underneath the driver’s side dashboard. Use the figure below as a map for your DLC (they usually aren’t numbered). The view in the picture below is looking straight into the cavities of the DLC. Notice how the DLC is tapered on both ends; we will be working on the wider row of cavities (1 through 8 in the figure below).
Use a jumper wire
to connect pins 4 & 8
2. Make sure there are metal contact pins in terminals 8 and 4 and connect the Data Line Connector (DLC) terminal 8 to terminal 4 with a suitable jumper wire (you can use a piece of thin electrical cable, speaker cable or simply U shaped paper clip; leave the jumper wire connected throughout the programming procedure). Make sure you know which terminals are 8 and 4. The vehicle will respond by cycling the locks (locking then unlocking doors) to signify entering of programming mode.
Figure a. Data link connector
3. Press and hold both the LOCK and UNLOCK buttons together on the first transmitter to be programmed. After about 15 seconds, the vehicle will respond by cycling the locks (locking then unlocking doors). Release the buttons on the transmitter.
4. Within one minute, repeat the previous step on the remaining transmitters to be programmed.
5. Remove jumper wire applied to the DLC (disconnect terminals 8 and 4).

More information about the data link Connector can be found here:
https://blog.carandtruckremotes.com/2012/06/06/what-is-a-data-link-connector-also-called-the-dlc/