2005 yukon denali doorlock problem

Ok first off my fault for not checking to see if the all worked in the vehicle first. I installed a Astrostart rss-5224 using a XK01 with AMDL 6.00 programed for type 4. I thought everything was working but did not check the back doors. the Front doors lock with the Transmitter but the back ones will not. I have also tried it with the factory FOB and same thing Is there a separate fuse and relay for the back doors and tailgate that might not be working. I have never had this problem before. Since i did not check it be for i have no way of proving it was not like that before. if anyone can tell me were to start to fix this it would be nice PS it starts the vehicle fine.

i have never heard of only select doors not working.  I have seen the XK01 type devices cause all kind of strange data related problems.  Have you tried disconnecting from the data wire of the vehicle.?  After disconnecting from the data wire,  Is there a way to reset the truck;s computer.  You may want to try that also.

i did not try to lock the doors manual and see if it still open

I've never seen this before, but, the two front doorlock motors are powered up by the Door Modules inside the doors, while the rear doors are triggered by the BCM under the rear seat. It couldn't hurt to do the following: 1, unplug XK01. 2, Disconnect battery for a few minutes, and reconnect. 3, see if that makes any difference.

I went and checked it out the back doors do lock and unlock, it just the lift-gate that is not locking. checked all the fuse and the relay in pillar b was working then listened by the lift-gate could here it lock and unlock with the push of the button not my problem anymore not because of the remote starter.