To repair power door locks, check if the circuit breaker, power switch and fuses are dysfunctional, examine the wires and power relay, and replace the parts as necessary. Replace the solenoid if voltage reaches it, and repair any wire short. Also, replace the batteries in the key fob, if required.
Begin repairing power door locks by checking the locks on all the doors. If none of the locks work, it indicates a dysfunctional fuse or circuit breaker that need replacement. If the other doors work, it indicates a dysfunctional solenoid.
To fix this problem, take out the door panel of the relevant door, and work the lock's switch to bring it to its unlock and lock positions. Examine the two wires for voltage going to the solenoid using a voltmeter. Replace the solenoid if voltage is present. Otherwise, inspect the wires running between the relay and solenoid, and repair a short or open wire.
When activating the lock's switch, if a click sound is heard, check if voltage is reaching the power relay from the switch. Also, examine the ground connection. If voltage reaches the relay but does not exit it, replace the part.
To identify a dysfunctional power switch, remove it from the door panel, and test for voltage. If voltage is present, examine continuity at the switch with a multimeter. Replace the switch if continuity is absent.
Otherwise, replace any short or open wires running between the relay and the switch, and fix loose connections. If there is no voltage at the switch, check for a short or open wire between the fuse panel and the switch, and replace as necessary.
To check for damaged wires, press the lock button, and open and shut the door slowly. If the locks operate, identify and replace the damaged wires.