Q: The remote or the inside unlock button will not lock or unlock doors

The door lock actuators that lock and unlock your doors can become weak and won’t have quite enough power to fully move the lock mechanism inside your door. This can happen for a couple of reasons. The individual actuator is failing or all the actuators may not be getting enough power. This can be measured as voltage with a multimeter.

If all four doors failed at the same time, I would suspect you have a problem at the power source or the lock/unlock relay. This is where you will need a wiring diagram from a repair manual to help you locate the correct fuses, ground connections and relays. There are two possible systems available for your year, make, and model. There is a premium version and the base model.

The base model uses a separate relay for the the lock and unlock function and the premium version uses only one relay. I suspect you have the premium version as the one lock/unlock relay could certainly produce the symptoms you are experiencing. It makes the most sense based on the description of your issue.

If you have the base version, you will need to check the voltage at each actuator. Better yet, find a common point that feeds power to all of them and begin testing there. If it is a bad power connection, it will be at a point that all the actuators utilize. If you have 12+ volts at each actuator, I would next do a voltage drop at the ground connections. Again, look for a common ground connection for all the actuators.

If the doors failed one at a time and not all at once, lets say over a period of months, I might suspect all the actuators have failed. GM door lock actuators are common failure item. I would only suspect this is your case if they failed one at a time over a extended period of time. For help having this diagnosed, a qualified professional from YourMechanic can come to your car’s location to inspect the lock problem.