Power button does nothing. Car worked a couple weeks ago. 12v is fine.

what scanner are you suggesting for communication with modules while the vehicle isn't powered on? i checked your post that sums of various scanners but this feature isn't listed in the charting.

to check power and grounds to the psc i have to pull the dash as I havent been able to get any scanner apps for my bafx elm1327 to communicate with my vehicle that will not enter acc mode. Which is why I was willing to throw a $20 part at it while the dash is apart. I checked for power at am1 and am2.

My dads a 30 year chrysler master tech so I may just bug him to help me diagnose it and I believe he has a couple aftermarket scanners that should be able to communicate with the modules. I know he has a snap on unit. I'll call him tonight. The dealer he works at also has a toyota location and he knows a few of the techs.


For sam spade he'll be enthused to know I charged my battery and it's sitting at 12.9volts now.

 

My dad has the handheld autel scanner, the thousand dollar one, I'm gonna pick it up from him tomorrow.

Today, after letting the prius sit with 12v positive clip detached. It powered on, with every check engine light on. I couldn't pull drivetrain codes due to elm1327 app issues, once i turned it off, it was dead again. A psc is on order, and I'll use the autel to wake modules up tomorrow.

 

Just an update. Picked up the autel maxisys ms906-ts from my dad. Tested it on my brothers gen2. It can indeed read like 5 modules with the vehicle powered off. When powered on it has a ridiculous amount of info and can graph stuff.

The ms906 connects very fast, just have to enter vin.

Took it home to test my problem prius. It too was able to connect and produce a fault! The psc is malfunctioning. It was only able to read 3 modules but i imagine that's because the others aren't being powered on due to the psc being messed up.

Included is two photos showing the code produced and how the maxisys looks in general on problem prius.

Prius has codes b2287 and code b2289 which also relates to the psc being unable to communicate with other modules. I will follow the manuals troubleshooting.

I ordered a used psc from ebay from a 2005 prius, comes in a couple days so I'll pull the dash and hopefully have my issues solved. Also been running a high powered fan in the vehicle to make sure everything is nice and dry.

Will keep ya'll updated! Hoping a wire didn't fry and it's just a dead psc.

 

I've since made a new thread
The car began working again, now is once again dead after a couple hundred miles of usage and several starts/stops.

It indeed was not the psc, it also is not the am1 or am2 fuse. Both have been changed. Measured front jump point at 12.4v couple days ago.

I just figured out the hidden location of the immobilizer(transponder key ecu) so i can begin testing the harness per servicemanual diagnostics for codes b2287 and b2289. It's behind the heater against the firewall. Both of those codes in general are basically unmentioned on this forum and google.

I'm concerned about a short or bad ground due to corrosion from moisture that built up from the hatch roofline leaking.

My project lithium battery was working just fine before the issue came back. getting 52mpg.

 

Just an update: went through the harness, following service manual troubleshooting guides in immobilizer and multiplex system. Grounds are good, i have power everywhere i should except pcon for my transmission. Car still had communication issues, wouldnt even go into igniton. gateway wasn't showing up in techstream, and same immobilizer codes as it did prior.

I did some more inspecting and found corrosion on some of the drivers side junction to the left of the combination meter. I sprayed them down(back and front of connections) with contact cleaner this evening and my car started right up after reconnecting power(after pushing the button ofcourse and letting it dry)

I'm going to put some more effort into cleaning the green copper oxide corrosion off and begin putting my dash back together. The Pcon fuse is good, and i have power past the engine side fuse box at the harness. Need to figure out where It actually stops at. I will check the wiring diagram but iirc it splits on the passenger side. Pcon also feeds the gateway which indeed has 12+ volts when the vehicle is off. I could just jump past it like a lot of people do to fix the parking lock code but I'd rather try some more in depth cleaning as i don't want to run into harness issues again.

I have an avc communication code i didn't have before but I have a feeling my radio didn't get plugged back in. I'll also check back of my mfd. Reasonably confident it's just something unplugged. As i didn't have the issue prior.


I'll keep this thread updated but I believe i found the issue, which was corrosion on few pins of connectors located drivers side.

 

Update: so i was getting a transmission P lock code and an obscure brake code saying low voltage. I finished cleaning the drivers side junction top left called IA3, which had visible corrosion on several wires/connectors. All of my issues and codes are gone. Vehicle drives great, techstream looks good. My radio was indeed unplugged on one connector and gateway code has cleared.

There's one new thing I've had occur. My fuel guage is flashing 1 bar. My tank was about 7/8th full. I took it out for a drive hoping it'd find signal and correct. Didn't work.

Previously it'd sense fuel level within a minute or two after power loss/battery reset. I also decided to top off my fuel tank hoping it'd sense the volume increase.

So I'm trying to find the section of the manual related to fuel guage. I know the issue is not the back of the vehicle, as it worked prior. It even worked when my car phantom worked perfectly a couple weeks ago.

What section of the manual can i find fuel guage information? I know i can search the wiring diagram but I've seen tidbits shared from searching on here. I already checked fuel system there's no information.


One final concern, my mini vci/techstream cannot complete a can bus check. Nothing shows up. They're zero errors and i have zero codes, and even two different obd2 scanners(bluedriver and elm1327) communicate fine. Though neither of them have a can bus check method. I haven't done a can bus check on my camry yet to see if it's software/cable related but will try tomorrow. I also tried the can bus check with ignition fully on, accessory mode, and the partial ignition(when engine doesn't run but ac/fans work)

I think it's either a software issue, or maybe i damaged the dlc3 connector somehow by front probing(i properly backprobed every other connector with matco backprobe kit)? Or worst case can is completely down but i think I'd be getting communication errors and gateway codes as some ecus only use can to communicate.


Sorry for the long post. Hope someone has some input besides the normal, "have you checked your 12v battery"(just kidding and being facetious. I appreciate everyones help)