2004 Venture keyless entry park lights won't flash

I just purchased a replacement keyless entry fob and I got it working but the park lights won't flash or work with the fob. What should I do.

Is the replacement FOB the same as the origional? Same numbers?

I just bought the van last week and the key fob that were given to me had the wrong part numbers on then. So I had to get a new one.

Did you purchase this van from a dealer? Is it new or used? If you purchased it from a GM dealer they should program the Fob's for you free. What happened to the origional fob's?

Yes I purchased it from a used car dealer but it wasn't a GM. The dealer had the wrong key fobs when I bought it, so they replaced only one.
I followed the programming in the owners manuall and I couldn't get the lock portion to work.

It depends on if your van is equipped with the BCM (Body Control Module), type 2, type 3 or type 4. I believe that only BCM 4 has the remote activation verification (Headlights/horn). I could be mistaken, anybody else want to chime in?

Thanks for your help I had to take to the GM dealer for service.