Chrysler Repair: Power door lock and back up sensor issue


Question
QUESTION: I have a 2008 Chrysler Aspen with 91500 miles.  I have 2 issues I hope to repair myself but am not sure what the causes are.

Passenger door lock will not stay locked regardless of how i lock it (fob, door button, manually).  It simply returns to the open position.  My thought was actuator but did not want to take door apart until I was certain.  All other locks work without issue.

Rear back up sensor lights work and there is an initial beep when an object is encountered. The problem is as I get closer to an object there are no more beeps when they should be getting quicker.

I really appreciate your help.

ANSWER: Hi Paul,
On the door lock, I wonder if you are thinking that is it not locked because the automatic door lock system falsely perceives that it isn't and so tries to lock it. This is usually caused by the door not being latched tightly enough against the door frame so that the ajar sensor tells the body computer to try and secure the lock. The solution is in the door frame where the latch 'striker' mates with the door latch. If you loosen a couple of screws on the striker and then move it in-board a fraction of an inch, then tighten the screws you may solve the problem by thus causing the door to press more firmly into the frame.
On the back-up sensor I don't happen to have the '08 Aspen manual but if I can find out about that in the minivan manual I do have I will send you a revision to this answer.
Please read the PS below and respond to it.
Thanks,
Roland

---------- FOLLOW-UP ----------

QUESTION: Thanks very much.  I look forward to the sensor response and will try the door lock recommendation.  Regarding the door lock this occurs even when we are driving and the doors auto lock.  It will go down and pop right back up.  Does that help at all?

Answer
Hi Paul,
I sent a revision to the first answer, so take a look at that again in re the back-up sensor.  What you describe as the behavior of the door locks is exactly what I would expect from either (or both) front doors not being firmly pressed into the door frames.
Thanks very much for the rating and nomination which if you would care to do again I would be most appreciative. The website allows you to give up to 5 nominations for answers that an expert provides.
Roland