Keyfob randomly stops working?

[noodle]

Hi all! Long time lurker. First time really posting anything but these forums have helped me out a bunch before so fingers crossed!

2016 BRZ limited manual. This issue started happening sometime earlier this year. My keyfob has no issues locking/unlocking the car when I grab the handle but occasionally the keyless start wont function properly.

I'll press down the clutch but the car doesn't recognize that the key is present (the green key icon stays off, doesn't flash or anything). What's weird is that if I press the start button, the car will go into accessory mode and the key icon will start flashing green (the icon is flashing, not solid). If I press the start button again, I can turn on the AC unit but the engine wont start.

I've replaced the keyfob battery once already and it seemed to fix the issue for about a month, then it started happening again. I've also tried holding the key fob next to the start button but the car will still fail to start.

This happens very randomly. It'll be good for 2 weeks, then randomly have issues for 2 days straight, then goes back to normal for another few weeks.

Car is pretty much stock, only thing I've changed out are some of the LED bulbs in the car (switched out about 3 years ago) and the head unit (kenwood DMX9706S) was swapped out 2 years ago.

If anyone has this issue or has run into it, any help would be greatly appreciated!

Been awhile :3.

I replaced the clutch switch and haven't had any issues since!

[humfrz]

Originally Posted by noodle

Hi all! Long time lurker. First time really posting anything but these forums have helped me out a bunch before so fingers crossed!

If anyone has this issue or has run into it, any help would be greatly appreciated!

Hello noodle and welcome to posting -

I would suggest you purchase and install another new battery (just to eliminate that possibility). Also, while you have the FOB opened up, I suggest you clean the battery contacts (like with alcohol).

If that doesn't do it it most likely have something to do with the keyless start system, which my car doesn't have - so, bout that thing.

Let us know if you get figured out or don't.

[CB750F]

Hi,

I kinda had the same issue, but car started with key near 'start' button.
I changed the battery twice because it would not recognize the fob as I walked up
to the car. So, try that, again. So far no issue but it's only been about 2 weeks
i since I changed the battery for a second time this yr.

[Yoshoobaroo]

Is it the correct battery? IIRC there’s a battery that is the same diameter but not as thick, so if it’s not the correct size it may not be making contact reliably.

[Tcoat]

I once had to go through four batteries in my wife's fob before I found one that actually worked. I think these things sometimes sit on racks for a long long time.

[noodle]

Thanks for everyone's input! The issue has stopped for now, but next time it happens I'll try swapping out the battery.

When this happens, the car wont start even with the key pressed against the start button.

I've found some potential info about the clutch switch, so I'll try targeting that next.

[soundman98]

Yeah,sounding more like the clutch switch. Another test is that a quick press on the start button with the clutch at rest(or a broken switch), and the key present is that the car should turn on the accessory circuit with the radio.