If you hear the buzz when you press the lock and unlock buttons as well as when your speed hits 15 mph auto lock then you have a bad lock actuator and the latch in the sliding door will need to be replaced to resolve your issues.
Town and country door lock making noise.
For some model years the actuator for the sliding door is available separately from the latch.
They could have constructed this a new way and cut the time by 70 to 80 but that s not up to the laborers and engineers dont care about ease of access.
In some cars a door lock actuator becomes noisy and produces a squeaking or buzzing noise when the power door locks are locked or unlocked.
If the electric motor or the mechanism inside the door lock actuator wears out the door lock may lock or unlock slowly or work sometimes but not all the time.
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