2007 Prius DIY Stuck

Wait a minute now I have dropped droplets of water in my inverter while the safety plug is out of the battery in the back doing this exact job never an issue I mean I blow the droplets of water out I drop a paper towel into the inverter literally and move air around with my blowgun and blow it all towards the paper towel that I've stuffed in the inverter maybe two of them in places and once that's done I'm going ahead and reassembling I don't know how you got inverter fluid in the inverter usually I undo of the 312 mm holding the inverter down and then I can literally pick up the inverter and twist it even bending the hoses and set it right on top near where the filler neck is for the radiator It sits there the whole time I'm doing the actuator I've done this like five times I'm quite good at it actually I can do this job in 2 hours and be sitting in the seat bleeding the brakes I'm not sure about the voltage business you need a Stout 12 volt I also usually don't take longer than 20 minutes to bleed the brakes so how people are getting caught up in this so long I'm not real sure how this works out while I'm doing the actuator replacement the car is off nothing is turned on there should be no load on the 12 volt any of that then after I have the actuator installed I put the heat pump the little electric motor pump next to the actuator I bolt that down I put the bracket that holds the air conditioning line back down everything ready to go I swing the inverter back around but don't put the bolts in it set it down plug up the orange and gray and black connectors behind the inverter and then with the car still off I have my buddy sit in the car and we manually bleed the brakes. Just like the old days no power nothing is on the remotes away from the car.

 

P0A09 points to an open circuit or short to ground on the "NODD" control-and-status line that connects the HV control ECU to the DC/DC converter. It runs from connector H16 pin 24 at the ECU to connector C5 pin 4 at the converter and is violet (at least in the 2006 wiring diagram I'm looking at).

If you don't find an obvious problem in the wiring or a connector, you might be right about some damage to the converter.

Edit: I missed this at first: P0A09 can have two different INF codes. If the INF code is 265, it is about the NODD circuit, as I described above. If the INF code is 591, it is about a different circuit between the converter and the ECU, called VLO (the ECU uses that circuit to request a reduced output voltage from the converter under certain conditions). VLO is a blue wire, running from pin 5 of C5 to pin 31 of H16.

 

In Pennsylvania with a few phone calls and a few looks through Facebook marketplace you should locate more inverters than you'll ever need for less than salvage pricing If you were closer you could come by and pick up one or two and take them home and they work It's rare to find one of these that's not working unless it's been removed and sitting out in the rain or some kind of nonsense uncovered. So you should be able to buy one of these from a Prius and somebody's yard for 50 bucks 75 tops The salvage yard up north in the Pennsylvania area I would imagine a hundred bucks because they took it off and they won't let you on the yard blah blah blah so shouldn't be a huge issue You do have all the plugs plugged up correctly and everything I mean they can only go one way some people forget to plug up the white connectors next to the rubber plug that passed through the side of the inverter when you take the cover off check your work.

 

The HV control ECU is inside the cabin. The DC/DC converter is inside the inverter.

One of the plugs you connect to the inverter (not one of the orange cables, just a low-voltage control/signaling connector) is called C5, and its pin number 4 is a violet wire. Runs to pin 24 of a connector H16 inside the dash that plugs into the HV control ECU.

That circuit has a name (NODD, only Toyota knows what they were thinking when they named it that, but the rest of us can make guesses; the ECU can use it to stop the converter—"No DC/DC", get it?). It's a strange arrangement because the circuit is bidirectional: the ECU can use it to tell the converter to stop, but also the converter indicates its operating status over the same circuit.

One of the things P0A09 can mean is a possible problem with that circuit. It could be as simple as a break in the wire or a problem at one of those connectors, or it could mean the converter is toast. I like to check for the simple things first. There are three pages in the repair manual giving you steps to troubleshoot that code.

Toyota Service Information and Where To Find It | PriusChat

Something I missed when I wrote post #3 was that P0A09 can have two different INF codes. If the code is 265, it's about the NODD circuit, as I described above. If the INF code is 591, it's about a different circuit, VLO, a blue wire between C5 pin 5 and H16 pin 31. That has a simpler, unidirectional use: the ECU uses it to tell the converter to reduce its output voltage a little, when that's appropriate.

Between those two INF codes, there are five pages of troubleshooting steps in the manual.

 

But I imagine another good clue is everything was working fine before you took apart the inverter undid the orange plugs and the 10 mm bolts and all of the plugs that go through the big rubber connector through the side of the inverter The plugs on the back and all of that so you could move the inverter to get the actuator out so more than likely all of that was okay If you got a few drops of water in there as long as you blew it out dried it out stuff some paper towels in there to suck it up and gave it time to dry that really shouldn't make any real difference I've left them open while I'm working on them and rain has gotten in them before I used the Shop-Vac to suck it all out and then I blew it with my 150 lb air supply in my compressor put it all back together everything was working fine

 

Both the NODD and VLO circuits go through that C5 connector, so yeah, this is a case where there's no conflict between looking at what the code is telling you and looking at the other good clue.

 

So you just closed it up with the water droplets inside the inverter near all those copper bus bars and that big black Hitachi instead of capacitors or whatever those things are I don't know if I'd do that I would try to blow that out suck it up with a paper towel something even if it was just light moisture You want that in there to be dry got a rubber seal around that silver lid for a reason even when you spray the engine off wetness doesn't get in there It's pretty serious voltage or you may have a wire pinched I don't know maybe lift the silver cover back up off the thing make sure you take the orange plug out of the back and have a look to make sure you haven't squashed a wire under the cap or any of that You're dealing with a I think a violet wire coming out of that C5 connector and then that runs all the way to the HVECU or whatever it is I doubt anything's happened inside the car it's got to be right there where you were working If you even think you're inverters bad you should be able to get one from myriads of places in your town junk yards whatever the things are almost worthless they have tons of them if you were close to me you could come here and pick you one out they rarely go bad so this is not a real normal thing you've got going on here that's why I'm wondering if you I don't know The water shorted something out a lot of times if you get the moisture out and dry it out hair dryer whatever and then check it again If this is the circuit that charges the battery the 12 volt then you should be able to just turn the car on and in ready mode measure the voltage at the battery it should be around 14.5 maybe you should do that anyway just to see what's happening If you don't have something like between 13.6 and 14.5 that circuit's not working and that's not good You're not charging your 12 volt.

 

You still have the same sub code?

 

The link in post 7 shows you where you can rent the electronic wiring diagram and the actual factory manual that tells you where various connector junctions are and Toyota's own troubleshooting methods for fixing it.

It saves a lot of time and guesswork.