98 buick parkave door locks dont work in the back they lock randomly

vats system . bad key or wire broken for ignition lock cyliner

it can be the bcm. body control module. it is located under the dash right next to the steering coluum

coulb be the control switch on your panel you can take the door panel off and check for loose connections and try to test for continuity. if you dont know how take it to a shop and have them diagnose the electrical. im quite sure it the switch that burnt out

may want to try this site as I could not find the exact psi, even though I ran across 54 psi but I don't think that is correct, Sorry Tim:

http://www.2carpros.com/makes/buick/parkave.htm

CHECK POWER WINDOWS 20 AMP CIRCUIT BREAKER.

i had the same problem on my accord 98 coupe 98.
and one day they stop working. i changed the engines of the locks and now the doors are working gr8!
hope it helps

cheers

YOUR RELAY OR RELAYS COULD BE FAULTY.

i dont see this as a major or even minor problem, why is it bothering you? if you wanna idle your car in drive whats the point? if your just waiting for someone to come in, put it in pak and the door will unlock BY THEMSELVES, sounds good to me, and then after the person jumps in put in in drive/reverse.... or u can simply leave it in gear THEN unlock it, the back doors dont have power lock button so they have to do it manually or if youre in park they dont have to do it at all. its a nice feature 1 in a million would actually not like this feature

First things first. Find out whats draining your battery. Systems with less than 12 volts can do very strange things.