P1151 What if I don't fix this?

Yeah its main purpose was for efficiency, but if the tank is busted and leaking, wouldn't that be a bad thing if you don't fix it?

 

Technically its purpose is to improve emissions (as opposed to fuel economy) so the primary consequence of not fixing this is that the car may not pass inspection in a state that requires it. At least where I have lived they just scan for trouble codes and fail the car if they find any. Otherwise you might take a small FE hit but I don't think it will be that terrible.

If it happened to me, I would want to fix it but I would want to find a way to DIY if possible.

 

I agree with you , I am not impressed with the tank, when I did drain it to change out the coolant I thought 12 hours would give me warm coolant which it wasn't.

I think its main purpose is to improve the emissions during the cold starts.

700 dollars would be better placed in some other part of your life to improve overall energy efficiency in my opinion. Someday someone will figure out how to bypass it and keep the DTC from appearing. Anyone know how?

Yes I would check out the system, basically the left side of the front bumper 'cover' needs to be moved to check it out.

web search; which for some reason does not copy here, said air bubbles may cause P1151 and that should first be ruled out .
See page 2-5 http://www.autoshop101.com/forms/Hybrid12.pdf Has some interesting info.

Two questions, have you tried clearing the code, does it immediately return, and do you still hear the coolant pump running on shutdown ( note under various conditions it won't run, depending on the different coolant temperatures I believe).

 

Wow that's very interesting. I thought the tank was supposed to keep the coolant hot for up to 72 hours. Usbseawolf had a video of him reading the temperature from scanguage and indeed the temp was 70C right at the start of the car, proving that the system worked.

 

I wonder if your coolant pump has been broken for some time, then? Do you hear any whirring when shutting down or starting up your car?

 

Well, after overnight here in Edmonton in winter the coolant in the tank is only around 20C, and I haven't gotten any DTCs. So it's more complex than just a coolant temp reading to trip that code.

I -thought- I read it watched the coolant temp when the pump starts and would set a code is it didn't change by "x" degrees. But even this can't be right, because after about 2 days in Edmonton winter the tank and engine coolant are the same temp.

I suspect it has more to do with the pump. I don't think I'll be fixing mine when it fails. It does nothing in winter. Except squeal.

 

[quote=drees;947534]I wonder if your coolant pump has been broken for some time, then? Do you hear any whirring when shutting down or starting up your car?[/quote]

I do hear a pump sound on start up/down.

I may have 'misspoken' about the temperature of the coolant. I remember it wasn't hot, and was bracing for the dangerously hot coolant. It was last spring and I just recall it wasn't hot but may have been warm. .

I wonder if I backed up the car out of the garage ( I don't remember where I parked that night ), the system did a quick cycle, which spread out the 'hot' coolant into the engine, absorbing the extra heat so I barely saw the difference when draining the coolant. A possibility.

Back to original topic, concerning replacing the tank, finding a salvage part is another possibility. Here is one on ebay, with a 650 buy it now price (don't do it)
http://cgi.ebay.com/ebaymotors/2006-Toyota-Prius-Coolant-Tank-Great-Condition_W0QQitemZ190331755577QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item2c50a81c39&_trksid=p4506.c0.m245

I am in general biased against the coolant tank, the increased complexity, the lack of protection from road hazards, the cost of repairing it for the low- in my mind- benefits. I drive my car for work around 6 hours a day, that is when I get the fuel economy benefits,doubling gas mileage of previous car.

 

Lack of protection from road hazards?

The tank is way on the side of the front of the car. It'll take a collision to even get to it.

I'd be more worried about the AC compressor / radiator. A good sized rock will put a hole through any of those.

 

This placement of the coolant storage tank (thermos) is the main reason collision insurance for the Prius is so expensive. It costs about the same as a mid-size SUV. It should be -a lot- less. But in minor accidents the thermos is destroyed and it's expensive to replace. The insurance bureau crash testers have posted that if you extend the -actual- front bumper, the part in the above picture behind the foam, about 12" on each side, it would protect the tank in most minor collisions and insurance would be a lot less.
Too late now though. It's not in the GIII so no worries there.

 

I can barely make out any of the hoses in the picture, might be my crappy laptop screen though.

Might I ask what type of road hazards you were referring to? Perhaps your definition differs then mine, since I'm more naive when it comes to driving experience.

When it comes to road hazards, I usually think of rocks and nails, and perhaps some branches, potholes, curbs, etc...

Anyway, I agree that the thermos sucks for what it does. An engine block heater is much better. A bit of hot coolant does barely anything to warm an ice-cold engine that's been exposed to the winter winds. Was more concerned about how it could get damaged, since Its my impression that the only thing that'll damage it would be on the scale of a pretty heavy collision, one that would total the bumper.

 

Re: P1151

The P1151 code has been coming on and off in my car and last time I used the AC it didn't seem to be working properly (cooled from 90 degrees outside to about 80 in car). Could this be related? Anybody? Thank you.

 

Re: P1151

No, DTC P1151 has nothing to do with the air conditioning. It appears your car has at least two unrelated problems.