Q: Having problems with door locks on 08 Cadillac CTS. Driver side door especially and will not lock or unlock with key. Others loc

asked by on June 05, 2017

I am experiencing problems with the door locks on this vehicle. The key does not lock or unlock the vehicle and power locks did not work on any doors. The module on the drivers side was replaced and all doors except drivers door locked and unlocked with main control. However, after a while all doors including driver side were inop. Problem with door lock appears to be intermittent except for driver side which is consistently inop.

My car has 150000 miles.
My car has an automatic transmission.

This is often related to a malfunctioning door lock actuator, a blown fuse or a faulty power door lock switch. When you use the door lock switch in the car it sends a signal to a relay which then activates an actuator inside the door. The actuator is the final step in the process in that it is a small motor with a set of gears that actually locks and unlocks the latch mechanism inside the door allowing the door to open. When this motor is bad, the latch mechanism will fail to operate and cause the door not to unlock as it is designed to. In the case of a bad door lock relay, the power, normally needed to send the signal from the switch when you activate it to the actuator motor is not there. This means the relay is not allowing the circuit to be completed and the actuator motor is not activated. Any of the above may cause your power door lock switches not to work properly and should be diagnosed by a qualified mechanic. I would suggest having a professional from YourMechanic come to your location to take a look at the door locks in your vehicle.

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