There is a problem with the transmission 'P' lock mechanism. Park your car your car on a flat surfac

Did you leave your door open?

 

The car isn't able to confirm that the parking pawl in the transmission has been pulled all the way out or that it is reliably moving from in to out.

Since you are able to move the car, obviously the pawl is pulled mostly out. That might be ok as long as it stays that way while you're driving. If it is somewhere near the tipping point of the detent spring and anything jolts it to drop back into the transmission while you are rolling down the road, that could be ... dramatic.

The cause could turn out to be just something like oxidation on an electrical connector in the park actuator circuit. Maybe the pawl has actually been retracted all the way and there isn't any mechanical risk, and the computer just isn't getting good signals to confirm it. But if I had a choice between looking at it sooner or looking at it later, I think I'd look at it sooner.

 

As folks mention, it could be a 'real' fault, but in my experience it is just a symptom of a weak battery.

When you power that car down without shifting to P first, after the engine stops, the parking Pawl should be motored into place by a small electrical motor. If the 12 volt battery is dead enough, it can't power that motor unless you are in Ready. (P, then Power down, instead of just Power down)

If so, you replace the 12v Battery and the whole Parking pawl issue goes away.

I would test the 12 v battery first. The best way is to measure voltage in a morning before you go to Ready.

 

Also on that note, if you have access to Techstream, you can ask the transmission control ECU what the issue is, and if it is supply voltage it will say that. There will even be freeze-frame data available showing what the relevant voltage was.

Because that's measured at the ECU, if it is reported low, there is also a possibility that a wiring or connector problem is involved, rather than battery.

What makes this case interesting is that the issue is being reported (and apparently withdrawn, and reported again) all while driving. Typically, the car is in READY when being driven and the system voltage is what the DC/DC converter outputs.

 

did you try placing your car on a flat surface and engaging the parking brake?

 

This happened to me at 11:30 pm two nights ago on the interstate. All dash lights light up and I get the "There is a problem with your transmission Plock mechanism . . . "

- That red triangle of death scared the sht out of me
- Pulled off onto the scenic overlook (packed with cars)
- Found this thread
- Went through that "MFD in Maintenance Mode" procedure
- Got to the menu that showed my 12V battery at 9.4V
- Started reading the next step and the Maintenance Mode went away
- Tried to get into Maintenance Mode 3 more times
- Two cars drove off thinking I was a drug dealer or a cop flashing my headlights to someone out there
- Couldn't get to Maint Mode so I said "fork it"
- Started up the car and finished the drive home with no issues whatsoever
- Plugged in the OBDII scanner and nothing

Are y'all telling me this is an indication that my battery is dying? That's a lot of "scared the sht" out of me for low battery voltage.

 

9.4 volts is definitely very low for a 12 volt battery, and down around the 9 to 9.5 volt threshold where various ECUs in the car (including the transmission control ECU) will start setting codes to tell you about it.

So while it's not necessarily all there is to your issue, it's certainly worth dealing with before assuming there's anything else.

 

Ya I get it. The battery is only a year old. Haven't had time to check it but my daughter's been driving it the last two days and there have been no issues.

 

Ok, folks, this has been happening to my 06 with over 245k miles on it. And I have been driving it anyway because it would go back off and randomly come on. Now it's just on, and won't go off. A diagnostic in manhattan where I currently reside is 400 bucks! I already changed the battery a month or two ago. That only fixed it temporarily. I am wondering if what caused it could be that I accidentally hit a curb on a ramp off the highway a few months ago. It was my driver side front tire that hit it going about 35mph. I would really like to take it to at least 300k ... please help? Also, could this be that I never replaced the transaxle fluid or some other fluid?

 

Time spent on guesses like that is time that could be spent just finding the repair manual sections for the trouble codes you have, and following the troubleshooting steps there to find out what the trouble is.

It sounds boring and prosaic and not as impressive as it would be to pull the right explanation out of the air. But it generally does get you to the right explanation.

Toyota Service Information and Where To Find It | PriusChat

 

I did actually look for this not only in the manual, but also here. Hence I also changed the starter battery. I am not a mechanic, and I have tremor in my dominant hand. So small seeming things like looking through manuals, and reading through many technical things, just are not possible. Otherwise I would not bother coming here and asking for help. I'm sure you meant well. But lets not assume that things which are doable for you are also doable for everyone else. Any actual knowledge or expertise would be greatly appreciated.

 

Aegean, that was actually really really helpful. I'm going to try this sequence to see if it works to give me more info on my red triangle of death. If it's just that wire, that could also have happened when I hit that curb ... maybe knocked it loose.