DTC P1121 Coolant Flow Control Valve Position Sensor Circuit Stuck: Description

WARNING: This page is about a different car, the 2007 Toyota Prius. However, it is still accessible from the selected car via links, so may be relevant.

Refer to DTC P1120 .

DTC DETECTION CONDITION

DTC No.	DTC Detection Condition	Trouble Area
P1121	Water valve position sensor output voltage: No change despite the ECM sending a valve control signal or slow response CHS tank outlet temperature sensor output: 60°C (140°F) or more (when hot coolant recovering starts) CHS tank outlet temperature sensor output: No change although the hot coolant is recovered	Water valve Cooling system (clogging) ECM

DTC No.

DTC Detection Condition

Trouble Area

P1121

Water valve position sensor output voltage:

No change despite the ECM sending a valve control signal or slow response

CHS tank outlet temperature sensor output:
60°C (140°F) or more (when hot coolant recovering starts)
CHS tank outlet temperature sensor output:
No change although the hot coolant is recovered

Water valve
Cooling system (clogging)
ECM