Having a strange issue. Taco CPU doesn't realize car is powered off

So this week, I started to have an unusual issue with my 2016 Tacoma. When I stop the car, I put it in park, pull up the handbrake, and turn off the engine as always—the engine powers off; however, sometimes the car's computer/electronic system doesn’t recognize its off. It thinks the car is still on and behaves like I have not powered down the car.

It beeps and when I exit the vehicle, shut the door, and when I try and lock it, I can’t. I get the message that says, keyfob not detected in vehicle. And I can't leave it because I can't lock it and I’m afraid the battery will die. This doesn’t happen all the time. It tends to happen after not using for a while, I mean like overnight-cold starts—and I essentially have to turn it on and off again until it behaves how it should or leave the car as is and do what I have to do quickly. The first time this happened was Monday. I immediately took it to the dealer, who ran a diagnostic, which showed no issues.

It also has this almost Michigan J. Frog like behavior. When I take it to the dealer it doesn't happen and they can't replicate it and therefore can't diagnose it, even though it's been happening all week. And now, when it happens, I pull my phone out to record it when I do, it stops and behaves as it should

Has anyone heard of this issue?

 

Disconnect the battery when not in use until the issue is resolved. If this becomes a long term unsolved mystery you could put a switch in to disconnect the battery.

 

Goofy question. Does it recognize that it's in park when you shut it down?

It will kill the engine and go straight to accessory mode if you turn it off and the shifter isn't in park. So if the dash isn't displaying that it's in park, then the trouble points to your shift position sensor.

 

How old is it
Edit... battery.

 

So it recognizes it’s in park until I hit the start stop button until that point everything is normal. The battery is about 2-3 years old.

 

what mods have you done recently?

 

Anything plugged in to the cig lighter? Had a similar issue with my gopro plugged in and charging from the cig lighter.

 

Definitely start w any aftermarket doodads or wiring jobs.
If that doesn’t do it, you might have to take it in, this could get tricky and need a skilled tech.

 

No mods. I do have a USB-c charger in the cigarette lighter. And I’ve had it for over a year no issues. But I did recently get a new 240w usb-c to usb-c cable for it. The only recent change.

 

I know a few of us have had this going on. Almost always there was a case of water penetration. With mine it would happen in rain. If it rained at night I would be awoken to the alarm going off and the interior all lit up. I found that one of the roof rack bolts was leaking and water was entering, going down the a pillar and to the many ecu's. Had it fixed and no more problem.....until. it started back up but this time it was a clogged ac drip line, so water from the ac was spilling over and actually going to the main ecu. Once the drain was cleared and molded to never clog, and everything dried. No more problem.

Tip. You can get the truck to fully shut down if you turn all head and fog lights off. That worked for many of us.

When this happens, check for moisture around the driver and passenger foot wells near the door hinges and also up near the center console.

 

Thanks so much for this. Do you know what specifically you had replaced ant he cost? I have had a bit of a leak after rain where the sunglass holder is. But mostly it's dry here. And that was a while ago

 

So I have an update on this. The issue is with a new USB-C to USB-C, 240W cable plugged into a charger in the lighter, and then into a phone to charge. When the cable is in the phone when the car is powered off, that is when the issue occurs. If you unplug it it does not.

 

wiseman say
look first where the human was last,,,, rarely fails.
Glad you got it figured out!