P1121 - Coolant Control Valve Replacement (with pics)

The noise you are referring to is most likely the CHRS pump. Audibe when the CHRS pump activates for a few seconds when the car is turned off and on. When the bearing is bad, noisy. You can still drive w/ the noisy pump. Mine has been noisy for 4 years. Will replace when it stops completely and the CEL appears.

 

I was used to the Prius being somewhat noisy upon shutdown. This all seemed to change when the CEL had come on because of the bad valve. The noise seemed to go way down and stayed this way for about six months until I was forced to make the repair for inspection purposes.

When I got my valve fixed, the noise seemed to return to normal. Maybe this was a coincidence as I thought the valve had something to do with the noise changing? What does it cost to get the CHRS pump replaced if the bearing is bad?

 

The CHRS pump is $127.46 at Camelback Toyota online. I don't know what a dealer would charge for the part and labor. My guess is $300+. You can call your local dealers to know for sure.

3-way valve is independent of CHRS pump and wasn't the source of the noise as you now know. The 3-way valve would be your source for lack of heat, if the valve was in the wrong position, and assuming no air bubbles in the cooling system.

 

Sometimes the CHRS pump will not run when the car is made IG-OFF. If the check engine light is not on, don't worry.

A small paper clip works fine to short the switched terminals of the CHRS relay socket. Use an ohmmeter to confirm which relay terminals are the relay coil terminals vs. switched terminals. Make sure you do not short the relay coil terminals in the relay socket.

The engine coolant pump is near the passenger fender and is turned by the serpentine drive belt and engine crankshaft pulley.
How to replace engine coolant pump and thermostat | PriusChat

 

Alright, thanks Patrick for your replies.

The pump is sounding pretty normal now that I have done the paper clip trick as suggested. My only concern now is the lovely gurgling-liquid-running sound that I hear upon start up. How do I make it stop? I really don't want to hear a waterfall running behind my dash for the rest of my poor cars existence. I've done several heating and cooling cycles. As noted above, I have gotten the coolant temperature above 180 degrees for a sustained period of time and I have opened up the bleeder valve multiple times. I've added back in likely more coolant than I took out. :-S However, I've only put it directly into the filler area not into the overflow tank like I read possibly could or should be done. Also the cabin heater is performing admirably. Is there something else I could try to do?

Thanks again.

 

Mine had exactly same sound after coolant change. But after 5…10 times of topping of coolant in radiator, while driving short trips, it stopped and has worked perfect after that.

 

Alright, I'll just keep doing that.

Thank you everyone for your help with this.

 

My family has 3 Prii. The 2 high-mileage ones have been throwing P1121 ever since I've owned them, over 2 years now. Since the check engine light was on, I connected an obdII dongle to them, to be able to scan for new codes, and kept rolling.

When my daughter's Prius, w only 106k mi, threw P1121, I figured I better figure it out. After doing this job twice, and getting ready to do it a 3rd time, I thought I'd throw in my 2 cents:

This job is very difficult. I can't recommend anyone who's not a great mechanic to even attempt it. The first job took me the better part of 2 days to complete. I would have aborted, but once you drain the coolant you're committed. And I knew I would save about $500 per car, so $1500 was worth sticking with it. The 2nd job took about 4 hrs.

The problem is you have absolutely no room to work. The vertical bolt that holds the valve to the car is almost impossible to get off. If you feel comfortable taking off or raising the inverter it would be much easier, but I didn't want to go there. And don't worry about and waste time trying to use pinch-off pliers and toilet seat screws (yes, read the thread, that's the mystery plug that was never revealed) to try and keep the coolant from draining out, I got a face-full of pink coolant on multiple occasions. Just drain all the coolant out right off the bat.

Just my opinion, don't do it if you don't have a garage full of tools and years of experience. It's well worth paying a pro a few hundred to do this nightmare job.

YY

 

Thanks to all for the information. I did this today based on this thread as well as some of the linked videos. Working in the tight space inside the car did require patience but I found that it was mostly straightforward. I did have one problem. When removing the 12mm nut, one of the two that holds the valve assembly in place, I sheared the bolt (or threaded post) it attaches to off. This solved the problem of removing the valve assembly as it came right out but there is now no way to attach the valve assembly at a second point. The 10mm hex bolt (lower in the engine compartment and gold in color) is now holding the assembly in place and the nub of the post above is keeping it from rotating. It seems pretty secure but there doesn't seem to be a way to easily replace that vertical post/bolt. (I went under the car thinking there might be a way to access the other side of that bolt but it appears to be inside the metal structure of the car and the access hole on the bottom that I thought would reach through to it turned out to have nothing inside of it.) So, I'm planning to just go with the single connector and check it periodically but if anyone else had this problem and has a solution for fixing that second fixed position, I'd appreciate hearing it.

Also, I'll mention that one of the videos for replacing the coolant (I think it was done as its own service and not as part of the installation of a new valve assembly) suggested raising the right side of the car to get the coolant to drain into the system and help with burping it. I did lift it on the right side about halfway through and I think it did help a bit. Just in case that is helpful for anyone else trying to burp the system at the end of the coolant refill.

 

I just finished mine and it was much easier than I expected. The hose clamps came off very easily in minutes with a pair of 12" long needle nose pliers--an essential tool for this job, I'd say. With my Mini-VCI working the coolant pump, it only took three cycles and about 1/2 hour to get the coolant back in that I drained (7 qts). The radiator bleed cock is essential--my Bentley manual says to route a hose from it to the overflow res and that worked nicely I just test-drove it and got heat in the cabin right away. I'll let it cool down and check level later.

I had a bit of a scare removing the side mounting bolt and just about rounded the head off with a cheap 10 mm wrench, but after a shot of penetrating oil and borrowing a better wrench it came out fine. (I was afraid of having the problem the poster above had, and couldn't see a good way to fix it other than removing the inverter to get more working space and re-tapping the hole.) Most time consuming was removing and installing the splash shields and figuring out how to remove the electrical connector. I could see the old valve was stuck in a half-open position. Best of all the CEL, which has been on constantly the last few days after a month or so of being intermittent, is finally turned off.

 

Thanks a lot, now I have to get me some Cable-Type Flexible Hose Clamp Pliers!

 

I changed this control valve in my car recently and one suggestion I have is when you put the hose spring clips/clamp back after replacing the valve, try to position it so that it is easier to remove next time. Removing it is frustrating if the clip positioning is awkward for a plier since space there is very tight. I still had 30K remaining (70k on ODO) on my coolant so I did not drain. Used harbor freight line clamps which worked well.

I also opened the old valve but could not see anything obviously wrong. Its all plastic gears and what looks similar to a plumbing ball valve (plastic) inside. The valve seemd to me to be too tight for the motor to turn. The plastic seemed to be yellowed so I think just degradation with heat/age.

 

This is procedure is covered by the dealer warranty. I just do not know how long. It is a common thing that happens.

 

Hi there Prius Pals,

Not sure who will see this. I was just told yesterday I need a new coolant valve. I am so relieved to hear this is not an easy do it yourself thing since I don't have it in me to even try. Valve is at the dealership waiting for my arrival early tomorrow.

I was actually told it's not a good idea to stall on this repair since the coolant valve helps control the temperature and could cause damage to hybrid system (my interpretation of what was said to me). Is this completely wrong? I'm adding it to my already high credit card debt because the last thing I want is to cause damage to my precious hybrid system down the road.

In the meantime I'm driving with the heat on just in case....ha! Yes, nervous Nelly has not changed one bit. : ) From reading posts I am seeing how ridiculous this is.

I see that older posts include quotes of about $500...ouch! I read through the wonderfully detailed DIY post and I'm now convinced my quoted price of $275 minus 10% disc isn't such a bad deal. Dealership manager said this isn't a common repair but looks like I'm not alone here at about 104,000 miles.

Thanks!
Maria aka Daisy

 

That valve has nothing at all to do with engine temperature control. A failure means the heat recovery system won't work, and all that does is pump stored hot water into the engine before it starts for lower emissions. It could also fail in such a way you'd have no cabin heat. This time of year, that's probably your biggest worry.

Another worry is driving with the check engine light on. You could get another, more serious unrelated code and you wouldn't know it.

After you get the car back, keep a close eye on the coolant level. Have the mechanic show you how to do that if you don't know. Bleeding air out of the system is hard to do, and even the dealer mechanics get it wrong sometimes. Have the dealer top off if needed. The Prius uses a special coolant made by Toyota.

 

Thanks, Andrew. Uh oh...this service manager usually seems pretty knowledgeable. Now I'm a bit concerned. He definitely said it's a valve that keeps hybrid system cool. Oh well...I'm very sensitive to cold weather and it needs to be fixed regardless. You bring up a very good point about the importance of engine light in case of another issue. Please no more issues. Better have them show me coolant level.

Another Prius chatter saves the day. : )

 

Earlier this year we had a member with lots of overheating issues (turns out he was loosing coolant through a blown head gasket), and the service manager was trying to tell him it was the fault of the coolant control valve. Ignorance of that valve seems to be endemic.

There aren't any valves at all in the hybrid cooling system.

Bottom line, if you're really strapped for cash and your heat works, you can probably put off this repair. (I delayed mine for nearly a year and half, but I had a code reader to check it every time it came up.) But that's really not a bad price.

 

Just get it fixed... I believe the total cost sounds right at 500. My 1121 was covered under the 10 year warranty, barely.

---Jay

 

Hi Jay, I'm assuming your repair (under warranty) was on a 2004-2007 Prius. Maybe even 2008? I'm being told Toyota fixed the coolant valve issue before manufacturing the 2009 although supposedly they redesigned the valve since 2009 manufacturing. Sounds a bit fishy to me.

I have a 2009 CA CARB Prius in a state that honors CA emissions warranty but Toyota is saying these parts aren't covered under warranty even though car wouldn't pass emissions with these codes. Warranty posted online lists specific parts they cover under Fed and CA emissions warranty.

I did get valve replaced for $275 thank goodness since now I'm dealing with P1116 code even after air in coolant was resolved. Confirmed P1116 (coolant temp sensor) again but engine light went off and hasn't come on again over past few days. I'm assuming I'll need sensor too but waiting until light comes back on again.

Has anyone had these parts repaired under warranty for a 2009 within the 10 yr / 150,000 mile CA CARB warranty? Please let me know. CA mechanic said they replace them in CA. Thanks!

 

A question for the crowd: I had my oil changed and fluids topped off a few days ago. The day after that, the CEL came on and it gave us P1121. Is there any chance the folks who did the oil change did something wrong that made this alert come up? Or is it just coincidence? Apologies if this is a dumb question--I'm learning.