python 881xp remote program problems

Hey guys, I'm trying to program another remote to my Python 881XP alarm system, but the alarm won't go into the program mode. I opened the door, turned the ignition on, and attempted to press the valet switch once and then hold it down, but the siren never chirps and the LED never blinks. I know the valet switch works because I am still able to put the alarm into valet mode. What other problems could it be? I have another car with the same alarm installed and I had no problems programming the remote at the time.

Check your door trigger, the green wire must be seeing ground while attempting to program!commit your way to jehovah and he will act in your behalf. psalms 37:5