Engine-Codes - Toyota - P1121 TOYOTA

P1121 TOYOTA - Coolant Flow Control Valve Position Sensor Circuit Stuck

Repair Importance Level: 3/3
Repair Difficulty Level: 2/3  What is this?
Table of contents

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 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

What is the cost to diagnose the P1121 TOYOTA code

Labor: 1.0

The 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.
How much do you know about cars?

Take the AutoCodes.com automotive tests and turbo-charge your car repair knowledge

Play Now

Possible Symptoms

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

P1121 TOYOTA Meaning

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).

More Information

Need more information on how to fix the P1121 TOYOTA code?
Get Access to Factory Service Manuals

Need more help?

Get the P1121 Toyota code diagnosed by a professional: Find a repair shop in your area