2006 Prius wuth p1121 error code and long trip tomorrow!

I'm pretty sure that this valve only controls flow into the thermos (the buzzing you hear when you shut the car off. This light could also be caused by low coolant. I would be more worried about where your coolant went. Look in the area of the water pump for leakage. If you find no leaks, you should be ok on your trip, the engine might take a little longer to warm up in cold weather.

 

You have a code.
You were abnormally low on coolant.
Yes, you risk damage.

Your vehicle, your choice. If the trip was an absolute must? I'd rent a vehicle. But until I knew where the coolant went, and why? I certainly wouldn't want to hop in and take a long road trip.

 

Remove the large black plastic panel over the radiator for access to the radiator cap. There are six plastic fasteners, rotate each fastener using a Philips screwdriver while exerting upwards pressure on the panel to pop the fastener out.

Remove the cap and see if there is any need to add coolant to the radiator itself.

If you are sure that P1121 is the only DTC logged, then you can take your road trip. However you should bring the coolant along and check coolant level when you stop for fueling.

 

Your vehicle, your choice.

I'd at least take the advice of Patrick Wong. -Check the coolant level in the radiator and travel with a supply, recheck as you travel.

On the "Positive" side, you are likely to find out pretty quickly if you have a bigger problem.

I'm just conservative in a situation like this. If I can negate or minimize the risk I'd do it. An 11 hour road trip is a bad time to discover that you have missed a fluid leak or have a more serious problem.

I'm taking a pretty simple approach. Until you are absolutely sure as to what caused the code and the low coolant level, you are taking a gamble with an 11 hour road trip. Therefore the only answer at this point to the question "Do I risk major damage?" is Yes.

If putting off the trip is NOT an option and/or renting a vehicle specifically for that trip is also not a viable option, then the advice to check your coolant level and travel with a supply and recheck, probably is minimizing the risk. The only problem being is that is a LOT of driving to do, without a totally definitive answer as to what may be going on.

Best of luck.

 

Then you should be good to go on your trip. Again I would encourage you to check engine coolant level (and engine oil level for that matter) when you stop for gas. Then when you return home, make plans to have the engine coolant valve replaced at a convenient time.

 

In a similar vein: does anyone know how long a Prius can last running it out of oil? It'd be an interesting experiment!

 

I'm not being sarcastic.

But check back in and let us know how the road trip went, and whether anything happened.

 

Keep in mind the correct fluid is the Toyota special red fluid which gives you pink salts on the water pump as a sign of leaking. Mine leaked for a while but is now holding at 125k miles. I wonder if the other poster meant if it could run without antifreeze instead of oil.

 

The engine coolant flow valve decided to get unstuck (for now.)

 

Be sure to read some of Patrick's threads on refilling with coolant. You can get air stuck in system, which heard by putting on the heat on and listening for gurgles. Maybe you need some time for the added coolant to work through the system air locks. Also did you add the right coolant?

 

Well glad to hear the road trip went well.
And now just good luck with the coolant flow valve.

I can't give you much of an answer here, as I have no idea what repair costs for that should range.