Intermittent power door locks not working properly issue?

Hi,

The first thing I though was related to a bad ground. However, if you look at pic 1, it indicates the ground for each door is at a different location.

So, the next thing would be power supply. The driver's door main switch ties all the others together via what is called a body control module. If the driver's lock always works, then I know it gets power which leads me to the body control module.

Before I would suggest replacing the body control module (BCM) I would perform what is called a CAN scan. CAN stands for computer area network. Basically, all of the control modules are tied together. This type of scan would help identify if the body control module is bad or not.

Here is a video that shows how it is done:

https://youtu.be/InIlnsjOVFA

That is what really needs done to confirm. The BCM is not an inexpensive part and I would not want to recommend its replacement to find out I was wrong.

Let me know if this helps or if you have other questions.

Take care,
Joe

I have almost the same problem (locking all doors with a key fob; unlocking only the driver's and back door/glass) with my Highlander 2011 (150K miles). The problem was present several months ago for a month, then disappeared, then came back a few days ago. I wonder what was the fix for your car? Thank you for any insights!

Hello, we need to do a CAN scan because it sounds like the body ECU is going out. I would remove the electrical connectors first to check for corrosion, disconnect the battery first. Here is a video to help and the main body ECU location so you can check it out.

https://www.youtube.com/watch?v=InIlnsjOVFA

Let me know what you find.