Key fob issue + physical lock issue

[Overdrive]

All right, I've got an interesting one for you guys. Did some forum searching and found things related to parts of my problem(s), but not all, so I decided to make my own post. As usual I'll try to provide as much info as I can as opposed to not enough, so apologies in advance for the length, but not for any dry humor.

TL;DR: keyless entry is not/barely working, fob batteries replaced with no real change, physical key does not work in the door, but remote starter works fine and does unlock the door. Interior door lock buttons and locks themselves work normally. Makes zero sense. Lots of cussing.

For background: It's a 2016 FR-S, auto. Being what it is there's no fancy BRZ-like fob, push-button start, no alarm system, etc., it's a keyed ignition and I've got the keyhole in the driver's door for manual operation of the door lock when needed, like the peasant I am. I do have the newer style (larger) Toyota/Scion key compared to the earlier version, so there are still keyless entry buttons, and I have a second spare key that I can count on one hand the number of times I've used, so it's essentially still brand new. I also have a valet key. The door lock actuators were both replaced last spring because the driver's side started going bad and not locking the door. No issues with that since. Final thing of note is when I took delivery of the car the dealer installed a remote start system (and I cannot tell you what form of witchcraft was performed behind the dash to make that happen, but it's there and it functions), so that's been on the car for the now 6 years I've owned it.

Okay, to the issue: After being away from home from the end of the summer until mid-December, though the car was garaged I was not able to put it on a maintainer, New England still manages to get ugly cold, and the battery died. Obviously keyless entry is a no-go in that situation.

My first real problem was that when I went to put the key into the door lock to manually open the lock, nothing happened. I can move the key in either direction, but it does not actuate the lock one way or the other. Pretty sure that's not supposed to happen even with a dead battery. I get the electrical side of things not functioning, but the whole point of the mechanical backup is pretty much this exact situation.

Needing to access the hood latch so I could get the car jumped, I was still able to open the trunk with the key and...do the needful. Car seems fine after getting jumped and a good long drive to recharge the batt. The key in the door still will not move the lock, but the keyless entry buttons are working fine for the doors and trunk lid.

About a week ago I noticed that the keyless buttons didn't seem to be working consistently, took a few presses sometimes, and as I was usually walking toward the car when this was happening I assumed the fob battery might be on its way out. Adding to my suspicion was being outside in temps around freezing, and though the key was in a pocket, two instances of that behavior were after being out in the cold and I figured it was killing the fob battery. But it has started to occur at other times and even on warmer days, could be shortly after driving the car and coming back to it or after it's sat for some time, even overnight. I can be standing right by the car door and get nothing. There doesn't seem to be any real rhyme or reason to it for when it happens now. Again, not being able to use the key in the door was problematic in these instances, because I wasn't always in my driveway worried about not being able to get into my car.

What I did find is that I can use the remote starter to start the car, and the fob for the remote starter is also used to unlock the door with a long button press once the car has been remote started. (After that, key has to go into the igntion, turned to On, and the brake pedal pressed in order for the car to stay running and be on your way.) After that the car runs and drives fine, but after shutting it down no guarantees that the key will lock or unlock the car. Honestly I do not use the remote starter very often at all, 99 times out of 100 I'll just open and start the car normally. When in the vehicle, whether it is running or not the lock switches on the door and the locks themselves operate exactly like they're supposed to.

I did replace the key fob batteries today on both keys (and in the short time of maybe 5 minutes going into and leaving the store to buy them, I came out to find the key fob not responsive, but had left the door unlocked just in case), but no change to the behavior. I pressed on the buttons a ton of times and finally got a response from each key, but that's not normal nor something I'm about to start dealing with regularly. I took the battery maintainer off the other car for tonight and hooked it up to this car to charge overnight, so I'll at least try to rule out the battery not being well charged causing some of the issues. But the part that really has me stumped is why the key is not working in the door anymore. That to me is unrelated to any possible electrical issues, because that should be strictly mechanical like it is for the trunk lid. I could be dealing with two or more issues that just happen to be affecting the same system.

If anyone on here has any advice, suggestions, more questions, your time and effort is much appreciated. I want to get a handle on this ASAGDMFP and try to narrow down what the issue(s) may be.

[Opie]

Problem #1: Physical door lock not working.
It's likely one of two things, either the door lock cylinder was replaced and not keyed to your actual key when the actuator was replaced, OR the lock cylinder has corroded and frozen in place. I would take the lock cylinder out and soak in WD40 or PB Blaster and see if it frees up. If it does then lubricate it with graphite and reinstall. If not, then make sure it is keyed to your key (if you don't know how to disassemble the cylinder and do this, a local locksmith can).

Problem #2: Keyfob buttons working intermittently
Sounds like the keyfob has just gone bad. Do you have a 2nd keyfob? Does it work? Probably need a new keyfob.

[Overdrive]

Originally Posted by Opie

Problem #1: Physical door lock not working.
It's likely one of two things, either the door lock cylinder was replaced and not keyed to your actual key when the actuator was replaced, OR the lock cylinder has corroded and frozen in place. I would take the lock cylinder out and soak in WD40 or PB Blaster and see if it frees up. If it does then lubricate it with graphite and reinstall. If not, then make sure it is keyed to your key (if you don't know how to disassemble the cylinder and do this, a local locksmith can).

Problem #2: Keyfob buttons working intermittently
Sounds like the keyfob has just gone bad. Do you have a 2nd keyfob? Does it work? Probably need a new keyfob.

Thanks for the reply, Opie.

I worked on the door lock actuators myself with a friend who has made a living working on cars professionally, so with him knowing wtf he's doing much more than myself he did the majority of the work, I was pretty much a glorified panel puller and tool gofer for most of it, and we verified everything was functioning properly after the job was done. The lock cylinder itself was not changed. I may have to go back in there like you suggested and see if anything happened to it. If it were frozen/corroded, would it still be able to turn in either direction or would it be stuck and unable to move?

I did mention that I have two sets of keys, one basically brand new because it's lived its life as a spare that I thankfully haven't needed to make use of. Both keys experienced the same problems interacting with the car, batteries were replaced in both, and both required several button presses before either one got a response from the car.

[Opie]

Originally Posted by Overdrive

Thanks for the reply, Opie.

I worked on the door lock actuators myself with a friend who has made a living working on cars professionally, so with him knowing wtf he's doing much more than myself he did the majority of the work, I was pretty much a glorified panel puller and tool gofer for most of it, and we verified everything was functioning properly after the job was done. The lock cylinder itself was not changed. I may have to go back in there like you suggested and see if anything happened to it. If it were frozen/corroded, would it still be able to turn in either direction or would it be stuck and unable to move?

I did mention that I have two sets of keys, one basically brand new because it's lived its life as a spare that I thankfully haven't needed to make use of. Both keys experienced the same problems interacting with the car, batteries were replaced in both, and both required several button presses before either one got a response from the car.

Yes, a lock cylinder can get corroded so badly it seizes, or moves a little but not the full rotation. Also, keys can get worn and no longer full engage all of the tumblers. Have to pull the cylinder to check bith of these.

The keyless would appear to need further diagnostics, maybe one of the keyless receiver modules in the car is going bad, or has something near it that is causing interference.

[Overdrive]

Small update: after charging the car for close to 24 hours, the keyless entry has been working fine (so far). I suppose it could have been that the car battery was low on charge, and while it had enough juice to start the car fine, perhaps it did not have enough to also run the transponder for the locks. We'll see if this particular issue shows up again, and either way it may just be time to proactively replace the battery.

[MeToo]

Good Morning. I was wondering if you had figured out what is wrong with the physical lock and fixed it? I am having the same issue and wanted to see if your solution would work on my car as well