Saturn Aura Locking Issue

Question

I have a 2008 Saturn Aura.

I've recently run into an issue with my locking system. When the weather gets warmer, 3 out of 4 of my locks stop working. Sometimes it's all 4 locks that have the issue, depending on how hot it is. The locks toggle a bit like they're trying to move, but they don't actually get to the position they need to. Furthermore, this issue is only occurring when I try to use my key fob and the lock/unlock button on the inside face of the door panel. This issue occurs when the engine is idling and when the engine is completely off. The locks work perfectly fine if I put the car into drive or park and they automatically lock and unlock respectively.

What is the most probable cause for my locks having the issue in warm weather and not cold? Why are my locks working if I put the car in and out of drive but not when I try to manually lock and unlock the doors?

Answer 1

The only apparent contradiction to this answer is that the door locks work when signalled to lock in park and drive. There is definitely some extra resistance in this system. It either mechanical and\or electrical. Can you move the locks manually with your hands easily? If not there may be some linkage lubrication or adjustment needed. There also may be some worn linkage. It would not be too uncommon for multiple door failure at this age. You may have electrical resistance. Do your windows roll up and down freely? If not you may have resistance from the alternator\battery circuit. This could be in the locking motors themselves. But I'm pretty confident you will find the problem in the circuit somewhere. You will find that there's a current supply problem (usually found in wires travelling between the drivers door and the cars body.) Or it could very well be a bad ground which can also be in the same area. You will need a multimeter and knowledge to use it to pin point this problem.