2004 Venture Pass Power Sliding Door Lock Issues

Hi,
I just got this 2004 Venture LS. Everything is pretty good, except there's an intermittent problem with the locking on the passenger side power sliding door.

The door seems intermittently to not want to lock when all other doors are locked.

I am aware of the programs for Last Door Locking feature, and the Driver Side Remote Lock/Unlock. However, I can't seem to figure the pattern here and wonder if any of you have had similar issues, and can point me to possible fixes.

When I troubleshoot, all the doors seem to lock and unlock, whether by the door switches or the remote. Odd times when I try the different features, last door lock (my wife does not ever use those features), the sliding door will stay unlocked. Then it stays that way for awhile. I traded her 2002 Town Country for this, and she's ticked that she can't lock the door by remote or switch, and must check it manually every time now.

After I give up and drive the car, I notice that everything is back to normal.

Is there a wiring issue? I've generally cleaned the contacts...there was crud build up, but that didn't seem to do it. Is there a BCM program mode that will get rid of this problem?

Thanks.

I have not tried this for this issue but have done this for other inter probs before. My thought here is that the lock solinoid is going bad.Follow me here, wire in a small dash light bulb with a coulple of leads to the exterior of that door. Just so you can see if the lock solinoid motor is getting power and ground everytime you tell it to. When your done you should have a small bulb sticking out the door panel someplace you can see it easily, now when you give the lock command you will know if it is getting to the solinoid because it will flash.