Power locks work in cool weather, intermittent in hot weather.

[cousindave76]

Using the remote or pressing the power switch on the doors will unlock/lock all 4 doors. Works great... in cold weather. When it get's hot outside, say about 85+ degrees, the door locks will randomly stop functioning. Drivers door always works. The three other doors seldom work. The lock wiggles a little, but does not complete a lock/unlock cycle. Again, this only happens when it's hot outside. Manually grabbing the lock and pulling up or pushing down is easy, there does not seem to be any binding or sticky issue with linkage. I've been searching around forums and Google for a while and have found a few discussions with similar issues to mine, but as the OP's of the posts near a possible fix, the thread stops and there is no resolution! So I'm calling out to those who have solved this issue. Please share your knowledge!

 

[SubwayGuy]

So the locks on the other 3 doors all wiggle, or which lock wiggles?

 

[cousindave76]

So the locks on the other 3 doors all wiggle, or which lock wiggles?

All three will wiggle, as if they are trying to perform their duty but can't get enough oomph behind them to follow through. This happens only when it's hot outside. All my locks work normally when it's cooler. I didn't mention this earlier, my trunk functions normally no matter the temperature.

 

[SubwayGuy]

All three will wiggle, as if they are trying to perform their duty but can't get enough oomph behind them to follow through. This happens only when it's hot outside. All my locks work normally when it's cooler. I didn't mention this earlier, my trunk functions normally no matter the temperature.

So the locks don't work well using the key fob correct? Do they all open if you hit the unlock button on the drivers door? I'm trying to narrow it down to the lock itself or your key fob.

 

[cousindave76]

Both the key fob and the button on the doors do the same thing.

 

[cousindave76]

I've been doing some research and found a different car having similar issues. The fault was in a temperature sensor that shut down the actuators if over loaded. The sensing (however it's accomplished) had just grown old and inaccurate. Is there anything like that on the Grand Prix? The only other possible cause I can find is a unit called the BCM. Now if only I knew how to find and test it.