Question for you folks who have "Smart Key" pushbutton start on your 4Runners: Have you ever had it fail to turn over when you pushed the button? It happened to me last night, and I'm still trying to figure out why. The details: 2010 Limited. Battery is good. All electronics worked, including the keyless entry and alarm. But when I got in, closed the door, held down the brake pedal, and pushed the button when the green light came on, I heard the solenoid in the dash (or whatever makes the little sound before the engine start), but then nothing. It's as if the anti-theft interlock didn't unlock. Called my wife and had her bring the spare key fob, and still got the same results. Multiple tries. Nothing.

I called AAA for a tow and waited with my wife in her car until the tow truck got there. (It was cold and her car has a heater, lol.) When the tow truck got there an hour later, I went to show the driver what was happening, and the dang thing started right up as if nothing happened. It has continued to start with no problems all day today. So I'm puzzled. What went wrong, and why did it decide to start an hour later? Any ideas? And please, spare me the "that's why I have a real key" comments. Your 5th Gen has about the same amount of electronics as mine, lol.

Simple things first. You say the battery's good ... how do you know this?
You can get it tested for free.

What about the battery connections? Clean tight posts? What about the battery in the fob? I'd replace that for sure. Check for mice?

If it were me, I would check the brake light switch and wiring. If it's not recognized as working, it won't start.

Good luck

Thanks for the suggestions gents. My answers are in-line.

The battery is less than a year old, with shiny tight posts and connections. No mice or other critters. The entire engine compartment looks like new. I've not had the battery tested yet, but every electrical accessory in the vehicle was working as usual that night, including headlights. (I typically leave the headlights in Auto mode, but turned them off when I first ran into this problem.)

The batteries in both fobs seem good, although I don't know their age. The red LED lights up when pushing any of the buttons on the fobs, and they also lock and unlock the doors as expected. same with the touch sensors on the door handles. I tried both fobs that night and got the same results with each. (I made sure one fob was out of range when trying the other, just to make sure I was testing them independently.)

I'll get the battery tested and buy new batteries for the fobs this evening, just to completely rule out those possibilities.

The brake lights are working, and the green LED on the starter pushbutton was lighting up when I'd push the brake pedal before trying to start it. The starter switch itself also seems to be functioning normally. I could cycle through all the various "accessory" modes with my foot off the brake.

And of course, this problem hasn't happened since that night. It has started without a hitch ever since. (I do software tech support for a living. I hate intermittent problems, lol.) I'm just glad it happened in the parking lot of my local pool hall, and not 20 miles of dirt road away from cell phone service.

Thanks again to you both.

When it did start, did it start right away, or sound like it was working at it? Now that it's working, can you test if the green light on the button only lights up when you depress the brake? That is, does it light up with the rest of the interior lights or only when it's "ready to start"?

If all the rest of the electronics modes were working, I'd suspect your starter or starter solenoid, personally. I know I've had starters in other cars that refuse to move in certain positions or at certain temperatures. Maybe check all those connections as a next step? And if it happens again, get someone to listen in the engine bay for a click or test across the starter terminals to see if it's getting voltage.

After the hour wait, it started instantly without any indication that it didn't want to. (That's how it has always started since I bought it last summer. Just a quick press of the button and it roars to life.) And the light on the switch doesn't go green until I hit the brake pedal. Temp-wise, it was only in the low 40s, and it has started easily in much colder weather this winter.

I'm wondering if I did something like hitting the button a split second before I hit the brake, causing the anti-theft interlock to kick in. Don't know if that's a possibility, but it's about the only thing I can think of.

It's happened a few times to me actually. I've had it even start and shut off. I wait a few minutes and starts just fine. Scary, especially when in the middle of no where. Mine is also a 2010.

For complete FOB failure or dead battery on the FOB



Also this

Thanks for the video and info, Danny. In my case, the fobs weren't completely dead - they operated the door locks like they usually do - but I'll remember that trick if I ever run into the problem again.

So does that mean anyone can start the vehicle even without a fob if they know this trick?

My guess is there's still NFC at play. Just like a badge reader at work.

Both key fobs that I received from dealership have the same issues at the same time, so I don't believe that the issues are with the Key fobs themselves.
The "key not detected" is intermittent and replacing the batteries in the key fobs does not seem to fix the issue. Using the tricks already described has helped with getting the car started but I would still like to have full functionality and not have a "key not detected" warning while driving. I also considered buying a key fob from Amazon just in case the issue was in fact with the fob, but it seems like the only options are $99 and up (which would strain my budget at this time). If anyone know of any cheaper options, please let me know. I purchased a couple of keys for an Altima that I use to have that also used push start, but it seems like those aren't compatible with the 4Runner (please correct me if I am wrong).

My car battery is about a year and a half old and I am 99% sure that it is not the issue. But I may get it checked out just in case.

So it seems like the issue must be with whatever is inside the car that receives the signal and it sounds like Toyota is the only place that can possibly solve this issue.

If anyone has any more information on what might be at the heart of the problem, I would really appreciate it. I don't think I can afford a costly repair from Toyota at this time.

(Note: I had my car serviced yesterday at a SpeeDee Oil change. The guy that worked on my car said that you can "reset" the system by using the physical key and turning the lock 3 times to the right and then 3 times to the left. After doing that, it should have no problem starting when placing the fob next to the push button. Just FYI in case anyone is desperate for solutions when the darn thing won't start.)

My wife's 2017 JGC had an issue that you couldn't start the damn thing without holding the key to the button. Never figured out what caused it. Traded it in a few months back.

I am surprised to see that a good number of people have had this issue without a lot being said other than it being a Key Fob issue.

Had a similar issue with my 2020 a couple weeks ago. I could hear the starter running, but the engine wouldn't turn over. Then got this error message "Smart Key System Malfunction". Was off pavement, but fortunately at a friend's ranch. No problem with entry or ACC mode, but it won't go to 'ON'. Stranded for 24hrs until we tried his error code reader, never got a code to come up, but he did get something cleared and it finally started.

Hard to believe Toyota didn't put in an override somewhere.

Took it to the dealer and they can't find anything wrong, but mine was not the first time they have seen the issue. Worse, they said there is no fix. Very disconcerting for a vehicle I plan to use miles from paved roads.

Will be calling Toyota customer service to complain, for what that's worth.