I replaced my coolant control value about 2 yrs ago after light/ code came on, about a month later light/code came back on, I replaced it again thinking I had put in a faulty one. I got about a yr and the light/code came back, I replaced it again. Now about 9 months later the light/code is back. Som…

What is the code in Pxxxx form, where xxxx is for 4 digits?

[image] Prius P1121: Coolant Flow Control Valve Position Sensor Stuck - Luscious... The second generation Prius, model years 2004-2009, uses a 3-way valve to control coolant flow between the engine, the hot coolant storage tank (thermos), and the heater core. Thus it’s involved in heating…

In 2 years the OP is getting ready to replace this valve for the 4th time. Replacing the valve is apparently not the cure.

Well, @KevinMerrigan did not tell us what the code is, it may be not even P1121 at all

For p1121, the most likely possibilities are faulty valve crud in cooling system eventually clogs replacement valve faulty tank outlet temperature sensor faulty water pump or relay faulty ecm faulty wiring harness My guess is the cooling system is rust & debris-clogged and it needs a thorough flu…

Yes, the code is P1121. That has been the code every time. Sorry, should have said that.

[image] George_San_Jose1: My guess is the cooling system is rust & debris-clogged and it needs a thorough flushing and refill w/ fresh Toyota approved coolant. That’s my guess too. Toyota original fluid is good for 10 years and 120K miles, but if it was replaced by any other (or “universal”)…

Thank you for all the responses. I will flush the cooling system this weekend and hope that my problem is solved.

[image] KevinMerrigan: I will flush the cooling system this weekend and hope that my problem is solved. make sure to use Toyota specific (red) fluid also, the process is quite involved form what I recall, as you also have to drain/fill the heat retention tank and to properly do all of this i…

2008 Toyota Prius - Coolant Control Valve

Maintenance/Repairs

Nevada_545 October 30, 2019, 5:42pm 10

You still have the factory fill in the cooling system? The inverter coolant also should have been drained and filled at 10 years/100,000 miles.

BTW, I have never drained rusty coolant from an aluminum engine.

Topic		Replies	Views
Toyota Prius Accelerator pedal position (APP) sensor Maintenance/Repairs toyota , prius	8	12943	November 12, 2013
P0711 Code: Can engine coolant thermostat issues cause this transmission coolant error? Maintenance/Repairs engines , gmc , yukon , transmissions , diagnostics	3	207	November 14, 2024
2009 Prius Check Engine Light On Maintenance/Repairs toyota , prius	26	34533	October 1, 2013
2004 VW, Check Engine Light Issue Maintenance/Repairs	1	294	December 2, 2008
2008 Toyota Prius, intermittent check engine light Maintenance/Repairs	3	1168	May 21, 2021

2008 Toyota Prius - Coolant Control Valve

Related topics