Engine-Codes - Toyota - P0125 2007 Toyota Prius

P0125 2007 Toyota Prius Code - Insufficient Coolant Temperature for Closed Loop Fuel Control

- Code Popularity: 6,964 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 2/3
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What are the Possible Causes of the DTC P0125 2007 Toyota Prius?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • Low engine coolant level
  • Leaking or stuck open thermostat
  • Faulty Engine Coolant Temperature (ECT) sensor
  • Engine Coolant Temperature (ECT) sensor harness is open or shorted
  • Engine Coolant Temperature (ECT) sensor electrical circuit poor connection

Code Tech Notes

If there are no coolant leaks, replace the thermostat first, if the problem is still there check/replace the coolant temperature sensor.

There is a factory service bulletin for the 2007 Toyota Prius:
2007 Toyota Prius Factory Service Bulletin OBDII Code P0125

⚠ Does your Toyota have Safety Recalls? → Check here

How to Fix the DTC P0125 2007 Toyota Prius?

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 P0125 2007 Toyota Prius Questions and Answers: Search here →

What is the Cost to Diagnose the Code?

Labor: 1.0

The cost to diagnose the P0125 2007 Toyota Prius 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.

When is the Code Detected?

The Engine Control Module (ECM) monitors the ECT signal voltage after engine start-up. If, after sufficient time has passed, the sensor still reports that the engine is not warm enough for closed-loop fuel control, the ECM interprets this as a fault in the sensor or cooling system and sets a Detected Trouble Code (DTC).
Example:
The ECT is 0C (32F) at engine start. After 5 minutes running time, the ECT sensor still indicates that the engine is not warm enough to begin active feedback control of the air-fuel ratio. The ECM interprets this as a fault in the sensor or cooling system and sets a DTC.

What are Code Possible Symptoms?

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

What Does the P0125 2007 Toyota Prius Code Mean?

The Engine Coolant Temperature (ECT) sensor is used to monitor the temperature of the engine coolant. The resistance of the sensor varies with the actual coolant temperature. The Engine Control Module (ECM) applies a voltage to the sensor and the varying resistance of the sensor causes the signal voltage to vary.

P0125 2007 Toyota Prius Code - Insufficient Coolant Temperature for Closed Loop Fuel Control

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