Troubleshooting a red triangle

Hello - this is my first time posting a problem here. Thanks in advance for any advice you can give.

I have a 2008 Prius, with SKS and Nav, and 103,000 miles on the odometer. I bought it from the original owner in 2010. So far it has been trouble free, with just oil changes and scheduled maintenance.

When I turn power on, I get a red triangle with exclamation point. Also a row of yellow indicator lights. Also along the top of the LCD display there is a red car shape with an exclamation point on it.

I followed the procedure for checking the voltage of the 12v battery using the diagnostic screens, using the procedure at weird-stuff-happening-mpgs-dropping-test-the-battery.73400/
and I got 11.8 volts.

Since it seemed likely that my problem is related to the (original OEM) 12v battery, which is now 6 years old, I took my handy jump-start battery thing (see photo below) and attached its red alligator clip to the positive post under the hood, and the black clip to the frame. I hoped that would allow me to start the car, but it did not start. The error lights on the dash were unchanged.

Question 1. Does the fact that the symptoms remain the same after I have connected my jump-start battery mean that the problem I'm having is NOT my 12v battery?

I then hooked up my cheap OBDII code scanner (see photo below) and checked for codes. It found none.

Question 2. Does the OBDII scanner not finding any codes have any importance? When people write about having their car towed to the dealer and having error codes read there, does that refer to OBDII codes, or are they referring to some other type of codes that can only be read by a dealer?

While I was in the diagnostic screens, I found three screens of error codes. The screens are called DSP-AMP, EMV, and NAVI. See 3 photos below.

Question 3. Do these error codes have significance?


Finally, further background on what led up to this red triangle, in case anyone with more technical knowledge can give me info on how I might have caused, and might be able to fix, this.

I followed the guide at Son of PriUPS for using an uninterruptible power supply (UPS) to power my house during power outages. The idea of the priUPS web site is that instead of buying a big gasoline powered generator, which is noisy and requires maintenance, it is cheaper to buy a big UPS which uses batteries that delivery 240 volts DC (same as the HV battery in the Prius). This UPS can be fed 240VDC from the Prius, which is a much quieter and more efficient generator than one that people buy to use during power outages. In addition to the author of priups.com, several others have used his method to carefully hook up their Prius to the UPS in their basement, thereby powering their lights and heat during outages. None of them has reported doing any harm to the car.

I finally hooked mine up the other day, and sometime after I connected the HV battery of the car to the UPS in my basement, that's when the red triangle came on.

I doubt that I damaged the Prius, since I protected it by mounting both a fuse and a diode in the cord connecting it to the UPS, to prevent overtaxing it or sending any voltage the wrong way. But I do realize that by tapping into its HV battery, I might have either broken something, or caused the car to sense something unusual going on and shut itself down. Now that I've disconnected the UPS from the car, I would like to know if I need to reset some sort of code in order to get it to start again.

One suggestion I got was to disconnect the 12v battery for ten minutes to see if that clears things up. Will try that in the morning.

 

Unfortunately I couldn't post any of the pictures I was referring to... or even a link to a picasa web album containing my pictures... because I don't have enough posts on PC. Will try again tomorrow. :-(

 

If I had enough posts that PC would let me post a link, I would mention that the pictures are at PriUPS

 

And as far as replacing the 12v battery, is the current thinking that it is best to
- buy the Optima yellowtop battery from elearnaid.com Optima DS46B24R Optima battery direct fit replacement for Prius 2004 + , Prius V & Plug-in Prius with Instructions (currently $173),
- buy the Optima yellowtop battery from amazon for $160
- or to just buy a regular 51 size battery for $80 and get the replacement ends from Amazon for $9, as recommended in the comments of the youtube video

 

Thanks for your thoughts. I believe there are two reasons why this is not the case.
1. I never plug the cord into the Prius until after the Prius is running.
2. Even if I were to accidentally plug in the cord before starting the Prius, the car would not detect high voltage, because of the diode I mounted in the cord between the Prius and the UPS. A diode is an electronic component that allows voltage to flow in only one direction (in this case, from Prius to UPS). It prevents any voltage from flowing toward the Prius. So when I plug the cord into the UPS, turn the UPS on, and then use a voltmeter on the Prius end of the cord, the voltmeter shows zero volts. This proves that the diode is working correctly.

 

Could you give me more information? What is a high voltage ground fault and what would cause that?

 

Actually, if you look at the pages describing the PriUPS system,
here PriUPS Update 26 September 2005
and here Prius Generator
you will see that it does not simply plug the Prius HV battery in to the inverter (DC input) of the big UPS in the basement; rather, it connects the Prius HV battery in parallel with a 240 volt string of batteries that are in the UPS. That's why the diode is there; to prevent the 240 volts from the UPS batteries from flowing to the Prius.

Could you tell me what "too small of a dc jumper" refers to? Are you saying the gauge of wire I used to connect the Prius to the USP battery string is too small? (I used the same gauge and length as several other PriUPS owners.)

Now I understand - the correct procedure is probably to connect the Prius to the UPS before adding the load (house lights, furnace, and fridge). Makes sense!

I am guessing that "reboot the 12 volt" means to disconnect the 12v battery from the car in order to reset some circuitry. I will try that.

Since the car won't start, getting codes read would involve an expen$ive tow to the dealer and a ridiculou$ diagnostic charge. Rather than doing that first, I'm inclined to "reboot the 12 volt" and see if everything works. If the car starts, the question then will be whether to bother to drive it to the dealer and pay them to read codes, or just chalk it up to experience and assume that no more warning lights means no harm was done.

 

Disconnected the 12v battery (by removing the negative lead from the frame) for ten minutes. Reconnected it and car started just as normal. Guess I don't need a new battery after all - at least not right now.

Thanks everyone for your comments - and kudos to edthefox5 for identifying the problem and giving me the (surprisingly simple) step to fix it!

 

You can see pictures of the wiring I added to the Prius (and all the wiring of the project, for that matter) at
PriUPS

There are two wires, which go from the two terminals of the HV battery to the two terminals of the UPS battery. That is all. There is no wire connected to ground or to the frame.