Alarm, no-start

Last night we drove our 4Runner home, shut it, locked it, etc. Just as normal with no issues. It was shut in our garage. This morning it has the alarm going off and won't start.

It is a 2019 4Runner SR5, bone stock. Zero modifications (not even new tires). It is just shy of 35k miles. The battery was reading 8.5V so it is plugged into the charger. However, I assume that's only drained due to the alarm, which was now reduced to a chirp of the horn.

I removed the S-horn and horn fuses just to stop the horn from sounding. There are no codes. Every door appears to be shut, including the tailgate. However, I cannot open the tailgate without power so I haven't tried opening it and slamming it shut, but it feels solidly shut.

The battery is currently charging so my next step is to see what happens when that's fully charged. Initially trying to start it did nothing, but after being on the charger for a bit, it clicked like it was going to try to start. I don't hear the fuel pump, but also am not surprised since the alarm was activated.

The security fuse looked fine. I haven't checked any others just because I didn't know where to start.

 

Any chance you have mousesessss in your garage?

 

Not likely. I don't see any evidence of any, anyway. It's a relatively new apartment complex garage.

 

Update:

After charging the battery, the 4runner started and died a few seconds later as if was shut off rather than a mechanical issue. It started back up immediately and I let it run for a while and drove it around the apartment complex lot.

My next test is to let it sit for a while and see what happens. I still have the horn fuse and S-horn relay removed right now. I'll post an update if I have anything further.

Coincidentally I scheduled the 35k service appointment last night and is set for Monday.

 

Update: after approximately 5.5 hours of sitting, the battery read 12.1-2 V and it started right up. I took it for a car wash and got gas all without issues. I guess the next step is to see if it remains fine over night.

 

Update:

I went into the dealership today for the regularly scheduled maintenance and mentioned the issue. They mentioned the vehicle keeps a log of approximately the last 10 trips, but I'd exceeded that since the issue. The battery tested low on CCA so I had them replace it. Apparently the new one, which is Toyota, has a 5 year warranty while the old one was only covered under the bumper to bumper warranty which was expired. Oddly enough, the new battery shows 12.2V when I just tested it. The old one showed anywhere from 12.1-12.7 in the many different times I've tested it. But with the warranty, I'm not too worried. Date of manufacture was 12/22 so it's not old, either.

As far as the alarm issue: it hasn't happened since. They said the panic button being accidentally hit was plausible, but they said the issue was likely caused by the battery starting to go bad. Although one of the service guys initially didn't think that could happen. Their default was to ask about modifications, remote start, or if the alarm was aftermarket; but, the vehicle is bone stock.

Anyway, hopefully that's the last chapter in this issue.

 

What temp was in the garage at the time of activation?

 

Somewhere in the mid to high 20's F ambient. No idea what the garage itself was, but it is detached and not heated so it had to be close.

 

We had issues off and on with random alarm activation.

#1
do you lock your runner in the garage ?
#2
You need to look at the hood latch and see if there is a single wire connected to the switch.

 

As in locked in the garage or is the 4runner locked within the garage? Either way, the answer is yes. The garage door is the only way in or out.

As for the hood latch, I'm not sure. It's a bone stock, base model SR5 (absolutely no add-ons). No doors, hood, or tailgate were open. What is the purpose of the wire?

 

The wire is attached to a switch in the hood latch.
We have had issues where the hood latch switch opens under cold temps causing the alarm to go off.
It got to the point I wouldn’t even charge for diag cause I couldn’t find anything. I just started changing the latches and solved every issue. It’s going to be impossible to duplicate.
If you have that wire and you disconnect that wire you will deactivate the alarm but still lock the doors etc.

Now with that being said.
Battery voltage is paramount to proper system operations. That’s the first thing anyone should check when starting a electrical system diag.
Low voltage will trigger strange things. I’ve seen it for many systems. I lost a lot of sleep chasing shit like this.
I would not be surprised if you didn’t have a problem going forward with the new battery.

The Previous info is for you to store in case she gives you a fit again.

You should know in a week if it’s fixed..
Have a good day…

 

One of the first things I did was make sure all of the swing panels (doors, hood, etc) were shut. But that's good information to have. I will keep it in mind if this ever happens again. Thank you