94 Q45 doors sometimes lock and sometimes don't, what's the 1st step to take?

[Q45dude]

I have a 94 Q45 and have noticed that lately when I lock and unlock the doors with the remote, they don't open or lock. For instance, you know how when you press the remote unlock button it only opens the driver door, I hear the click sounding its opened the door but when I pull the handle the door is still locked. I lock again with the remote and try again and still the same. So I just use the actual key to open. But sometimes everything is back to normal and all doors work.

what's the first thing to look at? where is this located? please be in detail with you answer. Thanks.

[Q45dude]

BUMP

[elwesso]

So it sounds like its trying to do something??

Im thinking maybe either the remote module, remote, or the drivers side door computer is at fault.....

[Q45dude]

So, how would I know which one?Where's the module located?