AutoCodes – Toyota – P0117 2009 Toyota Prius

P0117 2009 Toyota Prius Code - Engine Coolant Temperature Circuit Low Input

Quick Answer

The Engine Coolant Temperature (ECT) sensor is used to detect the engine coolant temperature. Common causes include Low engine coolant level, Faulty Engine Coolant Temperature (ECT) sensor, Faulty engine coolant thermostat. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P0117 2009 Toyota Prius indicates Engine Coolant Temperature Circuit Low Input.
Common causes: Common causes include Low engine coolant level, Faulty Engine Coolant Temperature (ECT) sensor, Faulty engine coolant thermostat.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 19,120

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jun 14, 2020

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0117 2009 Toyota Prius Description

The Engine Coolant Temperature (ECT) sensor is used to detect the engine coolant temperature. The sensor modifies a voltage signal from the Engine Control Module (ECM). The modified signal returns to the ECM as the engine coolant temperature input. The sensor uses a thermistor which is sensitive to the change in temperature. The electrical resistance of the thermistor decreases as temperature increases.

OBDII Code P0117 2009 Toyota Prius - Engine Coolant Temperature Circuit Low Input - AutoCodes.com — P0117 2009 Toyota Prius Code - Engine Coolant Temperature Circuit Low Input

What does this mean?

What are the Possible Causes of the DTC P0117 2009 Toyota Prius?

Low engine coolant level
Faulty Engine Coolant Temperature (ECT) sensor
Faulty engine coolant thermostat
Engine Coolant Temperature (ECT) sensor harness is open or shorted
Engine Coolant Temperature (ECT) sensor circuit poor electrical connection

How to Fix the DTC P0117 2009 Toyota Prius?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What does this mean?

Code Tech Notes

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

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0117 2009 Toyota Prius code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P0117 2009 Toyota Prius code?

Need more information on how to fix the P0117 2009 Toyota Prius code? Get Access to Factory Service Manuals

Need Help with the Code?

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0117 2009 Toyota Prius Code

1. What are the common symptoms of OBDII code P0117 in a 2009 Toyota Prius?

The common symptoms of P0117 include poor fuel economy, overheating, rough idling, and a decrease in engine performance.

2. What causes the OBDII code P0117 to trigger in a 2009 Toyota Prius?

The P0117 code is triggered when the Engine Control Module (ECM) detects that the engine coolant temperature sensor signal is lower than expected, indicating a low input from the sensor.

3. How can I diagnose the cause of the P0117 code in my 2009 Toyota Prius?

You can diagnose the P0117 code by checking the engine coolant temperature sensor, inspecting the wiring and connectors for any damage or corrosion, and testing the sensor's resistance and voltage.

4. What are some possible repair tips for fixing the P0117 code in a 2009 Toyota Prius?

Repair tips for resolving the P0117 code may include replacing the engine coolant temperature sensor, repairing any damaged wiring or connectors, and ensuring proper coolant levels and circulation.

5. Can driving with the P0117 code in a 2009 Toyota Prius cause further damage to the vehicle?

Continuing to drive with the P0117 code may lead to potential engine overheating, decreased fuel efficiency, and engine performance issues, so it is recommended to address the issue promptly.

6. Is it safe to reset the OBDII code P0117 in a 2009 Toyota Prius using a diagnostic scanner?

Resetting the P0117 code using a diagnostic scanner may temporarily turn off the check engine light, but if the underlying issue is not fixed, the code is likely to reappear.

7. How much does it typically cost to repair the P0117 code in a 2009 Toyota Prius?

The cost of repairing the P0117 code can vary depending on the cause of the issue, but it may range from $100 to $300 for parts and labor.

8. Can a DIY enthusiast fix the P0117 code in a 2009 Toyota Prius?

Depending on the DIY enthusiast's skill level and access to tools, it is possible to fix the P0117 code by replacing the engine coolant temperature sensor and checking for any wiring issues.

9. Will the P0117 code in a 2009 Toyota Prius affect the vehicle's emissions?

Yes, the P0117 code can affect the vehicle's emissions by causing improper fuel mixture, leading to increased emissions and potential environmental impact.

10. How important is it to address the P0117 code promptly in a 2009 Toyota Prius?

It is important to address the P0117 code promptly to prevent potential engine damage, overheating, and decreased performance in the 2009 Toyota Prius.