2008 Allure (LaCrosse)CX rear power door locks

[Gibbyman]

My rear door locks only work when they want too. More often not than working. Doesn’t matter if I use key fob or manually push lock buttons on door. Any ideas out there? Or similar problems????

 

[oldcarowner]

I have had trouble with mine after 11 or 12 years. Mine were intermittent and were worse in the summer when the temps were 95 F. I eventually replaced a couple of the actuators and that fixed my problem. I was able to look at the signal at the actuator with an oscilloscope and verified the signal was there but the actuator wouldn't work.

One thing you might try is spray some lube on the actuator's moving parts that are accessible and see what happens.

If you decide to shotgun one of the actuators stick with the GM branded ones. I used the economy version from Rock Auto on one of mine and it only lasted 1 year.

 

[Gibbyman]

I have had trouble with mine after 11 or 12 years. Mine were intermittent and were worse in the summer when the temps were 95 F. I eventually replaced a couple of the actuators and that fixed my problem. I was able to look at the signal at the actuator with an oscilloscope and verified the signal was there but the actuator wouldn't work.

One thing you might try is spray some lube on the actuator's moving parts that are accessible and see what happens.

If you decide to shotgun one of the actuators stick with the GM branded ones. I used the economy version from Rock Auto on one of mine and it only lasted 1 year.

 

[Gibbyman]

Ok can I test at the actuator with a fluke digital multimeter? And if so is there a +12v constant and the module gives it a -ground signal?

 

[oldcarowner]

Ok can I test at the actuator with a fluke digital multimeter? And if so is there a +12v constant and the module gives it a -ground signal?

It is a 300 millisecond 12V pulse. The control module generates the ground. When locking it puts 12V on one side of the actuator and grounds the other side and when unlocking it does the opposite.

 

[Globetrot1]

When a specific door lock goes silent, slows down, or is intermittent, it's the actuator most of the time.

I've had 3 out of 4 go bad. The most inconvenient one was the driver's door actuator. I've had 2 out of those 3 replaced, for the front doors.

I've had good luck with an electrical shop that has done some work for me. They were replaced over 2 years ago. I believe they used Dorman products. But they are holding up. OEM GM replacements might be the best option for peace of mind.

I'm hoping that, with all the problems actuators have caused, more recent ones are better put together.