Engine-Codes - Toyota - P1121 Toyota

P1121 Toyota Code - Coolant Flow Control Valve Position Sensor Circuit Stuck

- Code Popularity: 24,257 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 2/3
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What are the Possible Causes of the DTC P1121 Toyota?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other 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)

Code Tech Notes

For Non-Hybrid Toyota Vehicles P1121 = Accelerator Pedal Position Sensor Range/Performance Problem. See: P1121 Toyota

There is a Factory Service Bulletin for the 2004-2007 Toyota Prius:
2004-2007 Toyota Prius Factory Service Bulletin OBDII Code P1121

⚠ Does your Toyota have Safety Recalls? → Check here

How to Fix the DTC P1121 Toyota?

Check 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 pins.

Search for P1121 Toyota Questions and Answers: Search here →

What is the Cost to Diagnose the Code?

Labor: 1.0

The cost to diagnose the P1121 Toyota code is 1.0 hour of labor. The diagnosis time and labor rates at auto repair shops vary depending on the location, make and model of the vehicle, and even the engine type. Most auto repair shops charge between $75 and $150 per hour.

What are Code Possible Symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)

What Does the P1121 Toyota Code Mean?

The 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).
P1121 Toyota Code - Coolant Flow Control Valve Position Sensor Circuit Stuck

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