Please Help! 2007 Toyota Prius P lock malfunction/ won’t ready

Hello, I have a 2007 Toyota Prius that I recently acquired that was in need of a new hybrid battery after sitting for too long. I replaced the 12v as well as the hybrid battery and now the car has a “p lock malfunction” and tells me to park the car on a flat surface and set the parking brake. The power light is orange and I can only press the button once and it goes on (accessory mode?) but a second push turns the car off. From everything I’ve read it should be two pushes for ignition/on with out foot press of the brake. Am I mistaking? Also, there is a light that flashes that looks like the gear shifter? On the left side of the dash after you have turn the car off, with the key still in. I can’t find anything about that anywhere so if anyone knows anything about that, it might help me solve my issue. I have tried everything I can find online about similar issues, such as rocking the car to try to get the car to lock into park (maybe the pawl is in between and parking lock isn’t engaged?) not sure if that was really going to work as I also read the Prius has an electronic pawl and a motor moves it in and out of place and sometimes it needs to be relearned? Putting the car in and out of neutral and park with or without jumper cables to try to get the pawl to “learn” where it needs to be. Nothing has worked. I tried a jumper wire from the p control fuse to the transmission control wire as well. I feel might be helpful to mention the car doesn’t shift into anything but neutral and I’m not sure it even does that because it doesn’t seem like it’s really shifting. Also, the parking button light never lights up green? Not sure if anyone can help or knows anything but it all helps I’m so stuck and would like to fix this. Thanks. I’ll add pictures later.

 

The voltage is good at both the jump point and the rear. I have this light I’m not sure means anything but I have attached a picture. Today i received a VeePeak OB2 reader to use with the Dr Prius app and was able to get the code P3102 the only code I can get. I have read stuff about tech stream being the best way to diagnose but I’m trying to figure that out, is it possible I’m not pulling all the codes without tech stream? I’m just not sure. Thanks for your response.

 

Okay that makes more sense do you think it could be the transmission control ecu itself? Or that would require further diagnostics to know for sure? Thanks for your reply.

 

Alright, thank you so much I have figured out my next steps. I’ll try to figure out the INF code and go from there. I’ll update with anything I find useful to diagnose or my solution.

 

Okay so major update. I followed the advice of SFO and o double triple quadruple checked the 12v. Let me explain, I got a brand new 12v for the car because I knew with the age of the battery and how long it had been sitting the 12v was toast. For kicks and grins I attempted to jump the toasted 12v with poor results. I was able to lock the car electronically which was nice. I installed the new 12v battery (took less than 5 minutes) and thought the problem would be solved. No, same issue. I tried to jump the new 12v, nothing. So, I took the new 12v out yesterday and trickle charged it back to a full charge and decided to put it in reading a soilid12.6 V. First I made sure all the connections were clean, I thought they were clean but I still cleaned them, then installed then new 12V and BOOM we have resurrected another one. It started up and I was able to drive it around to get a good charge back on the hybrid battery after I put some fresh gas in and oil the good stuff so now I can put it back together freshen the fluids and she will be a daily driver again. Long story short check the 12v always check the 12v. Thanks to everyone in this forum I wouldn’t of made it without you or the support of my amazing wife.

 

There was a bit of corrosion, I thought I said that I my post… it seemed like very little corrosion to me and I didn’t think it would cause an issue. It was either that or my 12v had a slightly low voltage at purchase? I’m not sure just check connections, corrosion and everything with the 12v first. I suspect corrosion was my problem.