spoolin01

I'm having a couple of door/hatch lock issues but I'll start with the driver door outer handle unlock sensing first. Car has 55K miles, no prior indication of this problem, but a couple days ago, a mechanism inside the driver door suddenly went bonkers while driving - lots of vigorous clicking that would go on for a few seconds, stop, then resume a few seconds later. Door lock (driver's side for sure, not sure about others) would randomly lock and unlock. This lasted 10-15 minutes while driving, then settled down and hasn't occurred in several outings since. However the driver outer door handle unlock sensor no longer works. All other locking and unlocking functions work (aside from the hatch lockout, which I think is a long-standing fault) - the interior and exterior buttons and the key fob all work as expected. No issue with windows or any other functions that I can tell.

Any idea how to go about diagnosing the problem? I'll take a look at the wiring harness where it passes through the door jamb tomorrow, and probably take off the door panel for a look, but I don't know what to look for besides the obvious broken wire or sign of shorting. Can the door handle sensor circuit be isolated and tested? Is the sensor something I can replace? TBH, I haven't even checked the fuses yet.

Alex Medeiros

How old is your battery?

spoolin01

2021, and not weak. When the initial craziness happened, the car was running.

Alex Medeiros

These days batteries can sometimes only have a lifespan of 2-3 years due to all of the electronics. I'd have yours tested just to be safe. When you start to have weird quirks like the one you're describing, that can point to the battery starting to go out.

spoolin01

I went out this AM to head up to where my tools are, and the display went bonkers flashing and sounded like the starter was just clicking. Battery 9.85V. I took a small scooter battery and enough wire and metal to create a parallel circuit for it, to get the car started. Running voltage was around 14.4V. After driving 17 miles, battery voltage was about 12.8V and the load tester read smack in the middle of the green range. I've load tested a few new batteries and I think this one showed higher voltage under load than even the run of the mill new batteries. It's a Duracell Ultra Gold flooded, 12/21 date. Guess I'll have to give them a look for any future needs. I usually just buy the Costco or Walmart sorts.

With all the doors closed, there was almost a 3A drain on the battery. Removing the trailer circuit fuse (I installed a trailer adapter a few months ago) brought that down to 0.8A. I tried removing the driver door lock motor fuses and a couple of others, but that made no further difference. With the information at hand I wasn't able to determine which other fuse might represent something in the driver door lock circuit. I began removing the door panel but was unable to figure out how to release it along the top edge, so that's where I left things for today. The disadvantage of having to do this at a remote location with no internet.

I'll fully charge the battery tonight and load test it again, but since the issue started with crazy noises in the door while driving, and there was no prior sign that the battery was weak even when not running, I'm focused on it being some problem within the door, the wiring going to the door, or some module that controls driver door locking.

Alex Medeiros

That trailer adapter definitely is a good place to start. See if the issue comes back when you have it disconnected for a little while.

spoolin01

Did a little more digging today, and have a guess as to where the problem lies. I got the door panel off, and began some testing with different connectors disconnected.

To recap, the current symptoms have been:
1 - driver's exterior door handle unlocking mechanism doesn't work (except with metal key). No response - no beep and no side mirror light flash - to grabbing the handle.
2 - tailgate does not lock. It always opens - manually or with motor assist, even when no keyfob is near. I've suspected this has been the case for a long time.
3 - all other interior and exterior lock switches and window controls work as expected.

If I disconnect the connector that sits right at the trailing edge of the driver's door - the one that goes to what I guess is the lock actuator, interesting things happen:
1 - the beep and light flash from grabbing the door handle returns, though nothing else happens anwywhere. For the moment I'm assuming that means the functions in the handle are alright.
2 - all doors except the driver's door lock and unlock with the interior switches.
3 - the tailgate now locks!!! It will only open using the rear button if the fob is present.
4 - all doors except the driver's will lock using the fob. None will unlock from the fob.
5 - the driver's door can still be locked and unlocked using the mechanical flip button at the interior handle.

From this, I'm going to get a new aftermarket lock actuator, or maybe a used OEM. I guess the problem could still be the exterior handle - there are several wires running from there and I don't know what all they do. I should have detached that connector, to see what effect it has. I also didn't remove the trailer harness, though the fuse for the trailer circuit is out. I'll do that before removing or installing anything else, but I think it's worth a gamble that the actuator is the problem, as the first attempt, and I want to get it ordered.

I still don't know what to make of the 0.8A parasitic drain on the battery - none of the detached door panel connectors made more than a small difference there. That seems high considering it would imply that sitting for more than a couple of days would drain the battery - which doesn't happen - unless there's something in the electronics that shuts that down further after some period of time. For now, I park the car with the negative battery terminal disconnected.

spoolin01

Some progress made, possibly fully resolved. I got a rebuilt door lock actuator from eBay, and the external handle unlock function was restored, the tailgate unlock-only-in-presence-of-fob was restored, and the parasitic battery drain went away. I can finally leave the vehicle overnight without losing a half volt or more. In the process, I found that the door lock cylinder was damaged, and though the metal key would unlock the door when partly inserted into the lock, it wouldn't go all the way in and would not turn except just barely. It looked to me like a screwdriver had been forced into the lock at some point. Don't know if that could have led to the later failure of the actuator. Got a lock and matching metal fob-type key from eBay, to install tomorrow.

I thought it was interesting that when I first got the replacement actuator installed, the external handle unlock happened with some delay and some intermittency - I might have to try a couple of times for it to work, or it would take a second or so of contact. After a few rounds though, it now works as before, consistently and almost instantaneously. I wonder if some sort of learning was going on in some control module, where for a few weeks there had not been a working unlock function.

samiam_68

Yeah, something similar happened to me a while back also. Someone jammed a screwdriver into the lock and got into the car looking for a spare fob, trying to steal the vehicle. Couldn't lock/unlock doors properly after that, battery kept draining dead overnight. Had to replace the lock cylinder with a re-keyed new one and that took care of all issues. The actuator was fine.

spoolin01

That's interesting. The lock mechanism itself is purely mechanical, unless maybe the damage caused it to sit in a position in the actuator slot that was causing a funky signal.

With the new lock, did you get fob-style keys, or regular ones? I bought a new cylinder from the dealer but it came with regular keys, which don't do me much good. So I took it back, for a 10% hit.

samiam_68

The damage caused the driver door not to be able to lock which left the car in "ready to start" mode which drains the battery much faster than when the car is fully locked. With the driver's door unlocked, the car never goes to full sleep mode.