Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2008 Toyota Prius TouringFACTORY OEM SERVICE PROCEDURE
Monitor Strategy
Potentiometer detection
MONITOR STRATEGY
| Related DTCs | P1121: Coolant flow control valve position sensor circuit stuck |
| Required sensors/components | Main: Water valve Related: CHS tank outlet temperature sensor |
| Frequency of operation | Once per driving cycle |
| Duration | 20 seconds |
| MIL operation | 2 driving cycle |
| Sequence of operation | None |
Tank outlet coolant temperature detection
MONITOR STRATEGY
| Related DTCs | P1121: Coolant flow control valve position sensor circuit stuck |
| Required sensors/components | Main: Water valve Related: CHS tank outlet temperature sensor |
| Frequency of operation | Once per driving cycle |
| Duration | 10 seconds |
| MIL operation | 2 driving cycle |
| Sequence of operation | None |
Factory Service Tools
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.