Coolant Flow Control Valve

The valve was supposed to be replaced and it sounds like the engine pump was replaced unnecessarily (unless the bearing was starting to leak).

 

It's not a sensor you need, it's a 3 way coolant valve. Yes that part online is probably $75.

I don't know what could have cost $330, an engine water pump would be about $100 parts price. Inverter pump would be about $150. They must have a huge part markup at their shop

 

Marcus, your situation sounds a tad sketchy here. As Patrick and JC have eluded, P1121 means a new 3 way coolant valve is needed. It's an easy swap, but the bleed of the engine coolant loop is tedious, even for an experienced Prius tech. If they wrongly changed out the engine water pump, it's not the end of the world as this is a wear item which typically needs replacing during a Gen 2 Prius' lifetime. You don't say what your current engine code is, but if it's still P1121, I'd run away as fast you can from a $1700 quote and head for a good Prius mechanic.

 

Have a 170K miles '05 just purchased the other day that showed the same check engine light. I too stopped in Autozone for an OBD-II scan and received the same P1121 code.



So what if the reason for the low/no voltage change is due to the sensor itself failing. Haven't gotten any manuals yet (just ordered) so I can't even be certain that this is the actual part that I'm referring to, but the only cooling system sensor that I found on Rock Auto was for what appears to be a fairly simple thermistor that they describe as follows:

SENSOR

Situation:

Thermistor performance is key to proper coolant temperature sensor operation. But on some OE-style temp sensors, the thermistor is encased in plastic and the life of the component can be shortened during the manufacturing process when excessively-hot material is injected into the housing.

Solution:

Airtex engineers solved the reliability issue by encasing the thermistor in thermal transfer paste formulated to transfer heat. The thermistor is attached to the connector housing using resistance welding, placed into a brass housing, and then the full assembly is crimp sealed to avoid thermal damage.
______________________________________________________________________________

This particular part lists with them for $35.79, but they also have a Beck Arnley version for $13.29 that seemed cheap enough that I was gonna order it anyway as a just in case. Any thoughts?

The prior owner btw claims that the car has been driven for quite some time with that same fault to no apparent bad end, and the circulating pump's action appears to be quite vigorous (although I've no way of measuring that exact flow, just observed thru the open reservoir cap).

Also interested in hearing what happened with the OP.

 

The coolant temp sensor has nothing to do with DTC P1121.

 

Figures. Checking other threads.

 

Well here's the thing... you paid to have an issue resolved, apparently they did not perform the work necessary to resolve the fault. You are correct, the CCV is the most likely cause (could be wiring etc, but that's nearly unheard of) and Toyota DOES NOT call that part a "pump". So, if you paid to have your tires rotated and they performed an oil change INSTEAD, should you not get your tires rotated for free then?? Yes.

P/N for the CCV is 16670-21010 and it cost me ~$60 SHIPPED from a well-known Toyota dealer. Labor and coolant might add another $150, unless they want to charge you for the whole day

 

Hi everyone, I'm new to prius chat. I've owned a prius since 2006 and it's got 211k miles on it. I got a red triangle warning light and check engine light lit up while driving. The dealer did the diagnostics and said the coolant flow valve has been clogged and the coolant storage tank is clogged as well. The quote I received is $542 for the coolant valve replacement and $2193 for the coolant storage tank replacement. I wanted to know if this is a rip off. Thanks.

 

I don't believe the diagnostic is correct. What are the codes the dealer got when they diagnosed the car?

Both of those items you mentioned should not give you a red triangle, it should only give you an check engine light (since they are emissions related). If you do decide to change anything, I would change the coolant valve first and see if that fixes your problem before going to change the coolant tank (thermos, which rarely fails).

Last time I had a red triangle with a check engine light, it turned out to be my inverter coolant pump that failed.

 

I agree with @JC91006. You should not get the RTOD for just a coolant control valve. You may or may not have an issue there (check engine light), but you also have something else going on (red triangle). The dealer should have given you the trouble codes that turned on those warnings. They are essential for a proper diagnosis. (Unless you have lots of money and just like replacing random parts. )

 

My advice is to find an independent hybrid shop and get a second opinion. 542 to replace a 3 way valve sounds a little high.

 

Thank you for the response. The dealer didn't tell me any trouble codes. Yes, I'm going to an independent mechanic to check it out this weekend.

 

Agreed. Now that I've done it myself and know the steps and pitfalls, I'd do it for about $300-350.

And I wonder how the tank would get clogged and, if it was clogged, why it wouldn't be a simple matter to flush it.