2016 Prius Temp light came on today

It happened to me and was fixed for free...
I would not mix the coolant...

 

Ditto; NEVER mix coolants - a chemical reaction may occur, gumming up your entire cooling system. Always go with OEM coolant or distilled water.

Have them pressure check your coolant system. This will tell you if your system has a leak; but NOT where the leak is. If it passes the test; just top-off and keep an eye on coolant levels for the next month or two. Check every gas fill-up minimum.
The level may go down a bit again; possible air in your cooling system being replaced by coolant. Top-off with distilled water. If it goes down a third time; the dealership didn't do the pressure test correctly - take it somewhere else and get it pressure tested again.
2016 and early 2017 had a TSB on the exhaust heat exchanger leaking - it's warrantee work - don't let them sell you something.

Hope this helps.

 

There seems to be an issue with the exhaust heat recirculation system (EHRS, not to be confused with EGR) system in some Gen 4s leaking coolant into the exhaust.

It puzzles me, because Gen 3 already had EHRS for six years and that system seemed to have no such common issue.

 

call toyota and ask for goodwill warranty

 

I had the same issue, dealership told me it was a blown headgasket and tried to sell me whole a new engine. I took it to a private shop for a second opinion and sure enough, it was the exhaust heat exchanger. I was over the 80k mile limit for Toyota to fix it (and I didn't trust the dealership with my car after they grossly misdiagnosed the problem) so I coughed up the cash for the repair at the private shop. Most of the pricetag was the part.

 

The TSB mentions CA cars have emissions warranty through 180 months/150,000 miles

 

NO; that's the Federal mandated minimum warranty. If your still in Ca.; your covered out to at least 150K miles and 15 years. Check here: 2016 Toyota Prius Manuals & Warranties | Toyota Owners and here: California Vehicle and Emissions Warranty Periods | California Air Resources Board

Hope this helps.

If all else fails; you can simply loop-out the exhaust heat exchanger. It may take a bit longer to heat the cabin, but it'll save you a lot of out-of -pocket money.

 

I own 2016 Prius at 46K (Sep 2022) Dealer replaced Exhaust pipe assembly(using this TSB - T-SB-0135-19) as there was recall.
after 6K later- now at 51K(March1st 2023) . Coolant light on and then engine stopped on highway.
I towed my Prius to Dealer.
Now it gave below codes and dealer said engine is overheating and needs new engine and Water Pump.
P00B111
P011511
P148F AND P319000
Please guide if above codes really says Head Gasket or something else.
Looks like tech at Dealership are not knowledgable at all. They just gave codes and washing off their hands.

 

There is no code for head gasket failure; it's a process of elimination. Start with the water pump replacement and watch the coolant levels for the next few weeks.
Who did the 50K mile service; they should've noticed the low coolant level.

Also check the engine coolant sensor and wiring for corrosion or something chewing on your wiring harness.

Hope this helps...

 

Dealer who did oil change and warranty fix (at 46K) of Exhaust pipe said they are draining the coolant to fix exhaust pipe replacement.
I can fill the coolant later, they are filling minimum required.
Here is the service record at 46K when they did Exhaust pipe Guarantee work.

 

Toyota recommends 5K mile maintenance intervals; especially if you don't know how to do it yourself!!! I've taught my kids how to check under the hood and what to look for at least once a month or every other gas fill-up. That way they can avoid expensive repair bills.
Find a honest Prius mechanic to help you out. If it's the exhaust gas heat exchange again; you're probably out of warranty. Texas is not a CARB state, and I don't know what your consumer rights law covers over there.
Point is that you need someone else to look at it, to determine what the problem is. It could be as simple as a coolant leak that you didn't notice. Hopefully the engine wasn't destroyed by the overheat. If you kept driving with the temperature warning lamp lit, rather than pull over right away - the likely-hood of damaging the engine increases exponentially.

 

hmm
they replaced Exhaust pipe saying it is under warranty recall.
Looks like Toyota dealers has to comply Toyota standards of 1 year coverage for any repair they did.

 

Dealers & even Valvoline etc are setting the timer for oil change for 3.5K.
As soon as Maintenance required light blink I take it to oil change

 

1. Can you prove that the exhaust gas heat exchanger failed again?

2. I don't know of any automotive repair shop that will give anyone a 1 year unlimited mileage blanket warranty on everything. Just because they looked under the hood. Please post that 1 year coverage claim.

3. What does 3.5K mile oil changes have to do with your current issue. Your maintenance lamp goes off every 5K miles. If you want to take your car to a mechanic every weekend; your free to do so - but it may be hard on your wallet.

 

I don't know of any automotive repair shop that will give anyone a 1 year unlimited mileage blanket warranty on everything. Just because they looked under the hood. Please post that 1 year coverage claim.

This what Toyota Customer service told me when I called them.
If any warranty repair is done. if same issue pops up again dealer will cover upto 1 year.

 

Can you prove that the exhaust gas heat exchanger failed again?

T-SB-0135-19 - clearly give details check for coolant leaks into Exhaust pipe.
warranty repair they did is based on T-SB-0135-19.

 

Yes that kind of report I was expecting from dealer.

but dealer did not provide any info.
They just said engine is over heating needs to be replaced.
Only thing they mentioned is pump also has to be replace.
They did not mention anything about coolant.
Dealer (Richardson , TX Toyota) just provided estimate of repair with diagnosis codes from CEL.
nothing more than that.

This is all I got from Richardson , TX Toyota Dealership for a 51K mile 2016 prius.