red triangle with tpms

welcome!
12.4 is low for a new battery. put a charge on it, and it should hold close to 13 volts.

if that doesn't fix it, you'll likely need tech stream

 

Tpms is not a related non start issue.

Other than red triangle, what other lights are on?

Did you mess with the Orange interlock on the hv battery?

 

I think there is a lot of misinformation here about replacing your 12v battery, I'm not sure why so many do it to fix a problem. It doesn't fix your problem but makes it worse when the codes reset/erase after you change the 12v.

Now that you've got the triangle again, read the codes and see where it points you. If the triangle is on, there are codes stored

 

check you tube on how to complete the interlock properly

 

That might be true, but a Prius with no problems will start on a battery all the way down to ~10.5 V.

Because it is the first thing that people respond to just about any post here, just like bisco above did.

 

because those of us who have been around awhile remember the threads by very knowledgable members who advised to always start with 12v health

maybe toyota has changed things since then

 

On a side note....all the (Toyota issued) technical manuals I have for the Gen 2, in the troubleshooting guides, they almost always have you verify the 12v system early in the procedure. I believe they spec 11-14v as being ok to continue, and as @dolj mentioned, I've surprisingly seen voltages slightly lower than that with no outward appearance of a problem. I think it was around 10.2 or 10.3? that I saw a flashing dash that had squares around the shift symbols. Flashing dash cleared up after a charge.

 

will all batteries measuring 10.5 volts static, drop the same amount under the same load?

 

Max,

Anytime the red triangle appears, there IS a code stored (except if it appears due to low oil...have you checked your dipstick lately?)

If your code reader isn't showing a code, its a code reader problem, not a Prius problem. Not all code readers are hybrid friendly. Most members here, who are DIY types, have copies of Toyota Techstream. Others have various apps on their phones that are prius friendly.

Are you able to post a photo of your dash when the lights are on? TPMS and the RTOD should not be inter-related.

 

Just like any other battery, voltage is not always a reliable indicator of capacity. One of the reasons I was very surprised the first time I saw those values in the Toyota manuals. I would have to look again to see what systems they require to be turned on at the time of the voltage check.

 

Toyota have not changed anything, it is is the poor interpretation, sometimes aided by "Chinese whispers", that is the problem.

It is not the issue of whether or not to check the battery health – that is a given, it is the arbitrary advice handed out infinitum to replace a battery that is not causing the problem or creating the impression a battery with less that 12.4 V is bad.

The criteria Toyota uses varies depending on what is being tested. The 12 V bus minimum requirement could be > 8 V; > 9.5 V; 10 – 14 V; > 11 V or 11 – 14V.

Other than, it is a good idea to charge a 12 V battery that has a static voltage less than 12.4 V, because that is good for the battery, it is not likely to have any bearing on any problem with which a poster is dealing, until such time the lower threshold reaches a level which the repair manual indicates it to be problematic.

 

The bold area just caught my attention. This situation of NOT STARTING again after being shut off is typically indicative of error code P0AA6 - Hybrid Battery Voltage System Isolation Fault.

It IS the only fault listed in the tech manual as preventing a restart to "ready" once the car is shut down.

Frequently caused by electrolyte leakage on an older HV battery, but could also be caused by any damage to the HV cables, water in HV connections in the engine compartment, a failing transaxle, etc. A proper diagnostic tool will read the code (and it's subcode to help provide further location information).

 

2005’s don’t have tpms lights. Wasn’t even an option back then.

 

Good catch on the year/tpms thing. I was thinking his "tpms" is probably the brake lamp. That seems to coincide more with the RTOD and makes more sense