P1121 TOYOTA - Coolant Flow Control Valve Position Sensor Circuit Stuck
P1121 TOYOTA Possible Causes
- Coolant Flow Control Valve (Stuck or Clogged Cooling System)
- Faulty Coolant Flow Control Valve Position Sensor
- Coolant Flow Control Valve Position Sensor harness is open or shorted
- Coolant Flow Control Valve Position Sensor circuit poor electrical connection
- Faulty Engine Control Module (ECM)
How is the P1121 TOYOTA code repair?Start by checking the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.
Tech NotesP1121 Toyota
There is a Factory Service Bulletin for the 2004-2007 Toyota Prius:
2004-2007 Toyota Prius Factory Service Bulletin OBDII Code P1121
What is the cost to diagnose the P1121 TOYOTA code
Labor: 1.0The cost to diagnose the P1121 TOYOTA code is 1.0 hour of labor. The auto repair labor rates vary widely across the country, and even within the same city. Most auto repairs shops charge between $75 and $150 per hour.
- Engine Light ON (or Service Engine Soon Warning Light)
P1121 TOYOTA MeaningThe Engine Control Module (ECM) monitors the position of the water valve based on the valve position signal that is output by the water valve position sensor (potentiometer), which is coupled coaxially to the valve. The water valve effects control in three steps as indicated above, and the ECM determines the position of the valve according to the voltage of the respective step. In order to ensure the proper monitoring of the water valve, the ECM checks for malfunctions with the combination of the output of the potentiometer and Coolant Heat Storage (CHS) tank outlet temperature sensor. If no changes occur in the valve position signal that is being inputted into the ECM or if the response signal from the water valve is very slow, despite of the ECM commanding the water valve motor to operate the ECM determines that malfunction has occurred in the water valve position sensor circuit, and sets a Diagnostic Trouble Code (DTC).
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