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How to test a door lock actuator

by GSTP Support 04 Sep 2023
How to test a door lock actuator

The electronic door lock actuator is a part in a car that locks and locks/unlocks the doors with an electric lock. A door lock actuator may need to be replaced for a number of reasons:

A worn door lock actuator can create a humming noise during the lock/unlock operation. When all other door locks are working, a door lock actuator failure will cause the door lock to not work.


How to Begin Diagnosing a Door Lock Actuator

Depending on the year, make and model of the vehicle, the power door locks can be stand-alone, controlled by the door lock controller or controlled by the body control module. If your vehicle is equipped with a separate door lock controller for the body control module, these units will generally not be able to lock/unlock all door lock actuators, not just one. If only one door lock actuator isn't working, it probably isn't the control module (but there are exceptions). If you experience inconsistent door lock operation, and your actuator is controlled by a module, first remove the module's fuse, then reinstall it after a few minutes. This corrects a common software glitch in vehicles from the late 1990s to mid 2000s, especially Chrysler products. If your power door lock starts working fine after a fuse reset, you have two options: when the door lock fails again, you can remove the fuse and reset it, or you can take it to a shop and update the door lock software Correct problems.

How to test a door lock actuator

To diagnose, you may need to remove the door cover, check the door lock interlock and test the voltage to the door lock actuator per the wiring diagram. Measure the voltage at which the power lock button is pressed. If there is voltage but the actuator does not work, the door lock actuator is damaged and needs to be replaced. If there is no voltage when you operate the power lock switch, you must use an electrical diagram to further locate the problem. Could be the master door lock switch, bad door harness, bad connector, bad control module, or just a blown fuse.

How can I tell which door lock actuator caused the alarm to sound?
If you suspect one of the door lock actuators is causing the rain alarm to go off, the first step is to check the seal above the door lock.

If the weather strip directly above the door lock actuator is not properly sealed, water may enter the door lock actuator.

You can see the gaps in the weatherstripping, which is the easiest way for water to get inside the door lock actuator underneath. By sealing these gaps in all doors and lubricating the door locks and trunk/tailgate lock, the random sirens in the car on rainy days were resolved.

Check that all doors close smoothly and that the "door ajar" lights go off each time they are closed. If the light comes on and goes off when one of the doors is closed, a switch on that door may be to blame. If any door locks appear to be rusted, it is best to lubricate them with a suitable liquid lubricant.

If no apparent fault is found, the problem can be diagnosed by your dealer. In some cars, you can use a dealership scan tool to see which door (or trunk or hood) triggered the alarm the last few times. If the scan tool shows multiple alarms being triggered for the same door, the door lock connector and actuator must be checked. Usually, replacing the affected door lock actuator will resolve the issue.

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