'p' lock malfunction

i think you'll need to have the codes read.

 

yes, either a dealer (probably a hundred bucks or so) or if you have an old laptop, you can buy a mini vci on ebay for $25. with toyota tech stream diagnostics.

 

Yes those codes are Hybrid Codes that a OTC will not report.

If you have a DVM check the battery voltage on the front jump points before starting the car first thing in the AM. Then push the ready button twice with NO BRAKE applied then your in ignition and full load on the 12 volt. Measure the jump points again.
Then make the car READY and measure the jumps again for charging voltage.

Report those 3 tests here.

 

1. You need to retrieve the DTC. Use Mini VCI.

2. After you have the DTC, if C2310 has been logged, study this thread to determine whether it is applicable.
Red Triangle was intermittent, now constant | PriusChat

 

Mini VCI is supposed to be shipped with cloned Toyota Techstream software on a little disc. In addition, the software is floating around on the web.

 

Most assume this is a 12v problem, which it often is, but not always. My P lock error comes with wet weather. See here and the linked threads. "There is a problem with the Transmission P Lock mechanism" when road is wet | PriusChat

Here's a wiring diagram of the shift control actuator. Notice there is a relay and related fuse. You could check these.

 

Everything you need is here, you just have to look for it. I often use Google to search this site as it works better than the built in engine. Here's a picture and a net trick for towing from dogfriend. The two fuses and relay involved are labeled P CON. With car off you should cycle these out and back in again to assure clean connections. If you can energize the relay measure its contact resistance. It should be in the mohms or 0 resistance as seen by a regular multimeter. If you're sure your 12v battery is good then you probably have moisture in the park actuator's connector.

 

My p lock occurs when the weather gets wet. Aside checking the relay and fuses I've made no attempt to fix as my car drives, inspection isn't till march, and I hope to buy a new car next year. If I did attempt to fix I would buy a used shift actuator on eBay and have my local garage put it on.

 

Just had the same problem with my 2006, was intermittent for a week then car just died with all panel lights on. Bought a new 12v battery, didn't help. Had no choice but to have it towed to Toyota where they replaced the parking shift actuator for $1200. My GUESS is that this is one of those electrical components that doesn't age well and it gets flakey (judging by all the intermittent problems noted on this forum). Higher voltage might help but I would think only temporarily. Wish I had asked for the old part, I'll bet there's corrosion and stuff going on inside it. BTW, I live by the beach.

 

That's a frustrating amount of $'s.

 

12 volt battery was dead, so I charged my 2007 Prius through the terminal under the fuse box cover provided for jump starting. Afterwards I get the "There is a problem with the transmission "P" lock mechanism Park your your car on a flat surface and fully apply the parking brake." with the red triangle. Also after the fact, I read you're only supposed to trickle charge through that terminal. Since I was charging at maybe 15 amps initially I was very worried that I blew some fuse. However after hours of charging the charge current fell to below 3 amps which seemed normal. I followed this procedure to start. I released the parking brake started the Prius and left it idle for awhile, after several minutes it shut off indicating the Prius sensed full charge on the 12 volt battery. So far so good. What might have gotten blown by chaging through the starting terminal?

 

Nothing. You can charge the battery through jump start terminal. There’s a (relatively) thick cable from that to the battery through high current fuse so no problem using it to charge the 12V battery. Prius 12V battery itself shouldn’t be charged faster than 4A and you should only use smart charger so it’s not overcharged.

 

After 3 months trying everything suggested in these posts I decided to replace every ECU I can get to and BRAVO!!! The 1st one fixed it. The Transmission ECU under the AC unit on the passenger side. Oh man, I’m a happy camper now!

 

Thanks for sharing this. If possible, periodically check back and let us know if the replacement is still keeping the problem away.

Congrats on your fix.