Diagnosing The Dreaded Prius “Red Triangle Of Death”

When you have the red triangle of death pop up on the dash of a Prius, you know it’s usually not good. There are many causes of this light. What did we find with this one? Most people automatically think it’s a bad hybrid battery. Is that what we found on this one? Come along this simple and effective diagnosis and learn how to find the root cause of this extremely common issue! We hope this helps. Enjoy!

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[Quickwaya]

@theroyaltyautoservice Thank you for the video and showing the flow. I spent 17 years spinning wrenches prior to leaving the auto and HD trucks service in 93 to move into commercial and residential HVAC-R service . (Was tired of constantly having to purchase more tools, stinking like diesel fuel, and looking like I spend my days rolling around in printers ink - too many inframe overhauls etc. lol.) However I have remained in some form of auto repair for family and friends.

Damn the technology changes and glad I left just on the issue of the need to buy more and more diagnostic tools. With that said I just 2 years ago wished I had some of the tools. Had my 2012 Ford Explorer that had two issues. One was an electrical issue (dead instrument cluster) and two a catastrophic engine failure due to a failed water pump. Replaced the engine with fully remanufactured. However got my ass kicked with the electrical due to not having the proper tools. (Thanks for pointing this out to all the importance of the proper tools and using them and rechecking after a repair). Though I got my ass whooped I triumphed lol though too much time spent. HVAC has now become the same and thankfully I am retired.

HOWEVER, I have my sisters 2010 Prius to help her with and I have no real experience of knowledge working on. It too has the triangle of death and the following current codes C1310, C1259, P0A80, C2175, C2122, C2121, C2124 (all but one TPS reports preasue. History Coes P0A80, B2312 (X2 passenger side & rear left window switch) B278C, U0155, U0142, U0293 - all smart key loss of communication (power source, IPC BCM B, EV Control / Hybrid Vehicle Control). I cleared all codes and all cleared and did not return with the exception of one TPS. My sister reports that she found mouse scat under driver and passenger seat and in glovebox. Im thinking wiring issue, yet this is but a guess and I still do not have proper diagnostic tools just using ODB reader with Dr Prius / Dr Hybrid. Any thoughts other than to take to a qualified shop LOL such as most likely / less likely, areas to look into, and test to do? Thanks

[dianepfeifer]

Thanks for removing the cap from the coolant so I could see actual movement!

[speedy_pit_stop]

Short and sweet, right to the point. Just how I like it.

[dogdooley]

I love how you don't assume what the issue is and throw parts at a problem.

[sollykhan]

As usual another excellent tutorial, to the point, no excess baggage, THANK YOU 🙂

[JimmyMakingitwork]

Yeah, the pumps are the most common failure item in these, next is the battery harness which corrodes and terminals break and of course cells can go bad which can be replaced individually. Scan data is super helpful in these, for pumps and variations of .5 volts between cells can cause codes and the red triangle of death, so it doesn't take much.

Nice work.

[alrifainidal]

Great diag for an electric water pump. Thanks for the nice work

[JimenezPerez]

I came here because of the kitten video. I stayed here for the Prius video lol. Subscribed.

[pontiacsrule]

I'm a DIY & don't know anything about a Prius. Thanks for the lesson. Good info to know.

[crasher]

love the hybrid diagnostic videos I am always wanting to learn more about them

[HYBRIDEVMASTERSGARAGE]

Great Demo & Presentation 🙂 Enjoy your Scope Skills !!

[ChrisHall]

Recently had this with a 2005 Prius, bought an aftermarket pump, hope it lasts!

[djmobileautoservices]

Quick and easy. Thanks for sharing guys

[Hybriddiag]

P0A80 or P0A93 are very common dtc, s on these inverter cooling pump and replace hybrid battery modules are i am dealing every day....

[MichaelMorehouse-jv]

Like your videos, learning a lot from watching them. But I am a shade tree mechanic. Just starting to learn the electrical side of the cars. All I have is a basic code reader, test light, and a couple of voltage testers. Can not afford the fancy gadgets you have. Do you have any pointers to help us small guys out.

[rodvan-zeller]

At 6:15, scope is a window into the circuit, always preferable, I use both scope and meter simultaneous, my preference.

[danieljohnson]

I had the red triangle of death illuminate last year on my 2010 Toyota Prius. I determined it was the high-voltage battery. Not an overly difficult job, even for a DIY'er.

[weldingjunkie]

I personally like to see how and where you connect and why. Ecu vs connector etc. I’m willing to bet the majority does. Thanks for sharing

[DependableAutoTruck]

thanks so much only have 1 customer with a prius has over 100, 000 miles haven't dont anything other than maintenance

[ozarkliving]

If all I work on is Toyota and Honda, what Scan Tool do you recommend? Is there one with a built in scope?