red triangle, yellow !, red car after running down 12v battery

I'd appreciate some ts advice. My 2005 Prius with 198k miles now has these warning icons:

dash
red triangle
yellow circle with !

mfd
red car with !

The car does drive normally, except that the cruise control will not function.

I did check the 12v bat and saw the voltage dropped to 10.9 while under slight load in ready mode as reported by my Scangauge. I bought a new battery from the dealer and put it in. There were no changes in the warnings, but the min voltage was now ~12.1v.

My problems started as I wrapped up a day spent changing the rear struts. I drove the car about 300 ft and things were normal. I played the radio for about 1 hour in accessory mode while I reinstalled the rear trim panels. I noticed the radio dropping out and then the radio quit. When I tried to start the car and got a dash full of icons. I noticed the dome lights were dim so I read the manual for jump start instructions and used a Schumaker emergency battery that I carry to start the car from the contact in the fuse box. I drove about 20 minutes with no problems, then the red triangle warning appeared. I saw codes on the scangauge and cleared them and the red triangle went away but reappeared the next day after about 30 minutes. I no longer get any codes on the scangauge, but the warning symbols described above remain, even after rebooting the car by disconnecting the 12v bat.

I did check the oil level and it was at the add 1 qt mark so I added some oil, but no change in warning lights. The inverter fluid level is normal.

I have a Mongoose clone code reader I have not tried yet. Will it be able to get codes the codes for these warning lights?

Can you suggest any other troubleshooting steps other than take it to the dealer?

Thanks for your help!

 

Thanks for the quick suggestions. I got the mini--vci and techstream running and got this dtc:

B1248 AVC-LAN communication impossible

I did charge the battery for ~8 hrs last night and in the morning drive I was free of warning indicators for 7 miles, then got the rde triangle and the yellow circle and !. I charged at work for ~7 more hours and had the same results, warning free for about 4 miles then the same warning icons. I don't know if its related, but I was pressing buttons on the mfd when the warnings appeared on the evening commute tonight.

Any thoughts on what I should try next? I saw little discussion on this dtc on priuschat.

 

I think I found the historical list of codes and pasted them below. I am still learning my way around techstream and may have missed some other important reports. Thanks again for your help.

 

I have made some progress on my troubleshooting but could use some more advice.

I found the battery fan is not working. I can charger the new 12v Toyota bat overnight with my new Optima agm charger to 13.8v, reconnect the neg bat cable and have no DTC. I fire up the Mini VCI and have it run the battery fan and it tells me ECU cannot perform the requested active test, then shows the red triangle fault.

The fan blower runs when connected to at 12v power supply. The fuse for the fan is good according to my dvm. I checked the 2 fan relays in the fuse box and the short relay was good but the tall relay was bad and did not energize or change state when I connected it to a 12v ps. I replaced the faulty breaker but the fan still does not run.

I did notice corrosion on the 4 pins in a rectangular connector attached to the blovwer bracket, apparently caused by a water leak as described in the link below.

http://priuschat.com/threads/battery-blower-fault-water-leak.93583/#axzz3GstCQolJ

I scrapped the pins with a scribe to clean them but still no joy with the fan. Should I replace the connector as some have done? I plan to do ring the connection today to see if my scrapping made a difference. Where can I find a wiring diagram for this connector in case I need to trace it further?

Today I plan to follow some diagnostics for the cooling fan that I found here
http://ww2.justanswer.com/uploads/skyvisions/2008-06-21_094224_05_prius2.pdf

I did check the inverter pump and see turbulence in the tank so I think its fine.

Is there any other advice you experts can suggest?

Thanks in advance.

 

Patrick was right when several days ago he suggested I may have disturbed some electrical component while installing the rear struts. It turns out I had knocked the battery fan relay out of its socket near the battery fan.

I had never disassembled the rear interior before so I did not remember what the wiring looked like back there. I was working through a detailed diagnostic for the battery fan and looked at the wiring diagram on TIS and saw that the battery fan relay was in the back to I started looking for it and finally noticed the empty socket and found the relay under one of the battery blower ducts. I must have jerked the relay out of the socket while pulling those ducts to do the strut replacement.

Earlier I thought I had tested the battery blower relay while checking the fan 2 relay in the engine compartment fuse box, but that was the wrong relay. I need to plan my work better so I am not rushing and so I will not make a make a mistake like this in the future.


What's missing in the pic above?


The blue relay in the middle is the battery fan blower relay that I accidentally knocked out of the socket.

Thanks again for all the help you gave me.

 

I found fan no. 2 relay did not switch and I replaced it. Once I realized this had nothing to do with the battery fan, I wondered what it controls and I believe it selects high or low speed for the radiator fan. Can I use the mini-vci to check to see if the radiator fan runs at low and high speed?