2010 LC doors won’t lock, need electrical system guru’s assistance

[Tommy Dwyer]

As the title states, I have a 2010 LC with 236k on the clock, and my doors won’t lock. At first the problem was sporadic, but now they won’t lock at all. Key fob, button on any door handle or lift gate, switch on interior of any door…nope. The doors won’t lock when I shift out of park into any gear as well. Curious symptoms..when I press the UNLOCK button on the key fob you can hear the actuators on every door “unlock”, even though the doors are already unlocked. Same thing when I shift into park. Another symptom…about the same time this problem started the backlight for the console gear indicator by the shifter would occasionally go out. If i wiggled the shifter it would come back on, but now it doesn’t. My preliminary troubleshooting has been to check fuses, new fob batteries , and also for water intrusion… nothing.
This one really has me stumped. For a 15 year old, relatively high mileage truck the electrical system has been flawless. Aside from this everything else functions. With the exception of LED exterior and interior bulbs there are no other electrical modifications.
Haven’t torn into anything yet, looking for a little guidance on this one…thanks in advance for any / all assistance!

 

[Sandroad]

Are you certain about no water intrusion? Even if historical and nothing is currently wet? Have you looked in the door sill channels and checked connectors for corrosion ? Your electrical gremlins are much like many others who have found corroded connectors. Sunroof drains, leaky windshields and leaky cowls can all lead to water inside.

 

[Tommy Dwyer]

Are you certain about no water intrusion? Even if historical and nothing is currently wet? Have you looked in the door sill channels and checked connectors for corrosion ? Your electrical gremlins are much like many others who have found corroded connectors. Sunroof drains, leaky windshields and leaky cowls can all lead to water inside.

Thanks for the reply. I’m pretty confident about water intrusion. I put the sunroof drains on my periodic maintenance check list some years ago after reading about issues here. One of the first things I checked was the connectors in the door sill channels, amazingly everything looks as new…super clean. Haven’t opened the cowl yet, but from what I understand a leak there will result in moisture on the passenger side floor. Never experienced that.

 

[Zill]

As the title states, I have a 2010 LC with 236k on the clock, and my doors won’t lock. At first the problem was sporadic, but now they won’t lock at all. Key fob, button on any door handle or lift gate, switch on interior of any door…nope. The doors won’t lock when I shift out of park into any gear as well. Curious symptoms..when I press the UNLOCK button on the key fob you can hear the actuators on every door “unlock”, even though the doors are already unlocked. Same thing when I shift into park. Another symptom…about the same time this problem started the backlight for the console gear indicator by the shifter would occasionally go out. If i wiggled the shifter it would come back on, but now it doesn’t. My preliminary troubleshooting has been to check fuses, new fob batteries , and also for water intrusion… nothing.
This one really has me stumped. For a 15 year old, relatively high mileage truck the electrical system has been flawless. Aside from this everything else functions. With the exception of LED exterior and interior bulbs there are no other electrical modifications.
Haven’t torn into anything yet, looking for a little guidance on this one…thanks in advance for any / all assistance!

Have you tried replacing the door lock actuators? These tend to fail after some use, and why the intermittent issue was happening before.

Were all the doors acting up before or just one?

If one goes bunk, all of them start to act up sometimes as well. So if you can pinpoint the one that went south first, that’s your best bet.

 

[Tommy Dwyer]

Have you tried replacing the door lock actuators? These tend to fail after some use, and why the intermittent issue was happening before.

Were all the doors acting up before or just one?

If one goes bunk, all of them start to act up sometimes as well. So if you can pinpoint the one that went south first, that’s your best bet.

That’s a good question, and no I haven’t . But that leads me to something I was just about to ask. Up until this point they ALL worked as they should, none of them were a problem. I was wondering if one going bad would render them all inoperable. As I stated before they won’t lock, but if I press the unlock button on the fob you can hear ALL of them “unlock”, even though they are already unlocked…same behavior when I shift into park. So my question…since ALL of the actuators exhibited the same behavior at the same time, and this coincided with the backlighting for the console gear indicator acting up and going out…is there a switch / contact mechanism on the gear shift (that all door locks would react to) that has gone bad.

 

[Zill]

That’s a good question, and no I haven’t . But that leads me to something I was just about to ask. Up until this point they ALL worked as they should, none of them were a problem. I was wondering if one going bad would render them all inoperable. As I stated before they won’t lock, but if I press the unlock button on the fob you can hear ALL of them “unlock”, even though they are already unlocked…same behavior when I shift into park. So my question…since ALL of the actuators exhibited the same behavior at the same time, and this coincided with the backlighting for the console gear indicator acting up and going out…is there a switch / contact mechanism on the gear shift (that all door locks would react to) that has gone bad.

Did you disconnect the battery from the car and let it sit for a few minutes to let the electrical system reset?

 

[Tommy Dwyer]

Did you disconnect the battery from the car and let it sit for a few minutes to let the electrical system reset?

I did disconnect the battery, but only for about 5-10 minutes as I had to use the vehicle to go somewhere. No change. On my agenda for this weekend is to disconnect the battery and connect the pos / neg leads for 30 to 60 minutes as I have heard that this will completely reset the system. If this is incorrect information please advise…wouldn’t want to make matters worse !

 

[Zill]

I’m trying to brainstorm.

Does your 2010 allow you to change the settings to make it so when you unlock the car, all the doors are unlocked rather than just the driver door?

If so, I would try to change that settings for diagnosis purposes to only unlock the driver door for now.

 

[Tommy Dwyer]

I’m trying to brainstorm.

Does your 2010 allow you to change the settings to make it so when you unlock the car, all the doors are unlocked rather than just the driver door?

If so, I would try to change that settings for diagnosis purposes to only unlock the driver door for now.

And I appreciate it! Yes it does, and that has been my default setting. I went in and tried every other option…no dice. On my 2010, if one TPMS sensor goes bad the entire system is inoperable. Warning light on the dash. If I could get confirmation that one actuator failure does the same with the door locks I’d start pulling door panels, but as far as I can ascertain from search on similar problems that doesn’t seem to be the case. That, and the fact that all actuators appear to “unlock” as they should has been searching for a single point of failure. I don’t have access to the electrical system schematics (and would have a hell of a time reading them if I did) but would like to see how the shift mechanism interfaces with the door locks.

 

[Zill]

When my driver door actuator was acting up (the only repair I have had to make to my 2016), it started up where only my driver door was not locking. Then eventually, it got bad enough where I would try and lock the car and it would have an extended beep and none of the doors would lock. Replacing just the driver door lock actuator did fix the issue though.

It’s usually the driver door that goes out since it gets the most use, but I can’t guarantee that.

I would hate to throw the parts cannon on this one, but I’m not much of any help on being able to diagnose it from an electronics standpoint.

I think the part was only around $150-$200 and 30 minutes later, it was fixed… but it’s a gamble. You’d probably spend $200 on a Toyota dealer tech to truly diagnose it though…

To note, my broken actuator would unlock, just not lock.

 

[Tommy Dwyer]

When my driver door actuator was acting up (the only repair I have had to make to my 2016), it started up where only my driver door was not locking. Then eventually, it got bad enough where I would try and lock the car and it would have an extended beep and none of the doors would lock. Replacing just the driver door lock actuator did fix the issue though.

It’s usually the driver door that goes out since it gets the most use, but I can’t guarantee that.

I would hate to throw the parts cannon on this one, but I’m not much of any help on being able to diagnose it from an electronics standpoint.

I think the part was only around $150-$200 and 30 minutes later, it was fixed… but it’s a gamble. You’d probably spend $200 on a Toyota dealer tech to truly diagnose it though…

To note, my broken actuator would unlock, just not lock.

While mine went from all to none rather than just one acting up then all, I’m inclined to follow your logic. Will do a little more poking around, see if anyone else has a thought or two, then probably start throwing money at it

 

[Zill]

While mine went from all to none rather than just one acting up then all, I’m inclined to follow your logic. Will do a little more poking around, see if anyone else has a thought or two, then probably start throwing money at it

Good luck! I would disconnect the battery for a full night and see if anything changes in the morning.

 

[Tommy Dwyer]

Good luck! I would disconnect the battery for a full night and see if anything changes in the morning.

Worth a shot!

 

[NikP]

Since you have some actuator movement when you press unlock it would suggest electrical is probably ok. First, I'd start with a good lube of all the door actuators. It could be as simple as little friction is standing in the way of them locking.

Next, I'd remove the door panel and pull the driver's side actuator out on the bench to see if it locks and unlocks. I haven't looked at one, but I suspect it has three electrical connections. One connection for ground and the other two connections are 12V+ when connected will trigger the actuator to lock or unlock. Pretty simple to run it through the cycle and see what happens.

This thread goes into more detail about actually just replacing the internal motors which is way cheaper than buying new actuators.

Failed Door Lock Actuator R&R

The front left (Driver's) door lock actuator in my 2013 decided to give up the ghost at 52,435 miles. I made a dealer trip yesterday to pick up the part since manually locking/unlocking the door was becoming annoying. Got the dealer (Groove Toyota) to beat the internet prices and sell the part...

forum.ih8mud.com

Also, I've attached the electrical schematic if it might help.