AutoCodes – Toyota – P1118 2008 Toyota Prius

P1118 2008 Toyota Prius Code - Coolant Temperature Sensor Circuit High for Coolant Heat Storage System

Quick Answer

This system uses an electric pump to supply hot coolant stored in the coolant heat storage tank into the cylinder head of the engine, in order to optimize engine starting combustion and reduce the amount of unburned gas that is discharged while the engine is started. Common causes include Coolant Heat Storage Tank, Faulty Engine Coolant Temperature (ECT) sensor for CHS (Coolant Heat Storage), Low engine coolant level. 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: P1118 2008 Toyota Prius indicates Coolant Temperature Sensor Circuit High for Coolant Heat Storage System.
Common causes: Common causes include Coolant Heat Storage Tank, Faulty Engine Coolant Temperature (ECT) sensor for CHS (Coolant Heat Storage), Low engine coolant level.
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 6,695

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

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Table of contents Created and updated by William Orellana on Apr 24, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1118 2008 Toyota Prius Description

This system uses an electric pump to supply hot coolant stored in the coolant heat storage tank into the cylinder head of the engine, in order to optimize engine starting combustion and reduce the amount of unburned gas that is discharged while the engine is started. Before the engine starts, the ECM operates the electric water pump to direct the hot coolant in the heat storage tank into the engine, in order to heat the cylinder head (this process is called "preheat mode"). The duration of the operation of the electric water pump is variable, depending on the temperature of the cylinder head. During the normal operation of the engine, the water valve opens the passage between the cylinder head and the heater and closes the passage between the cylinder head and the tank. During preheat mode in which the cylinder head is heated, the water valve opens the passage between the tank and the cylinder head, in order to allow the coolant to flow from the tank to the cylinder head. At this time, in order to warm up the intake port quickly before the engine is started, the coolant flows in the reverse direction

OBDII Code P1118 2008 Toyota Prius - Coolant Temperature Sensor Circuit High for Coolant Heat Storage System - AutoCodes.com — P1118 2008 Toyota Prius Code - Coolant Temperature Sensor Circuit High for Coolant Heat Storage System

What does this mean?

What are the Possible Causes of the DTC P1118 2008 Toyota Prius?

Coolant Heat Storage Tank
Faulty Engine Coolant Temperature (ECT) sensor for CHS (Coolant Heat Storage)
Low engine coolant level
Engine Coolant Temperature (ECT) sensor for HST harness is open or shorted
Engine Coolant Temperature (ECT) sensor for HST electrical circuit poor connection
Faulty engine coolant thermostat

How to Fix the DTC P1118 2008 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 is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P1118 2008 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 P1118 2008 Toyota Prius code?

Need more information on how to fix the P1118 2008 Toyota Prius code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P1118 2008 Toyota Prius code diagnosed by a professional: Find a repair shop in your area

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 P1118 2008 Toyota Prius Code

1. What are the common symptoms of OBDII code P1118 in a 2008 Toyota Prius?

The common symptoms of OBDII code P1118 in a 2008 Toyota Prius include the engine running hot or overheating, a decrease in fuel efficiency, and potentially a check engine light on the dashboard.

2. What does the OBDII code P1118 indicate for a 2008 Toyota Prius?

OBDII code P1118 in a 2008 Toyota Prius specifically relates to the Coolant Temperature Sensor Circuit High for the Coolant Heat Storage System.

3. What are the possible causes of OBDII code P1118 in a 2008 Toyota Prius?

Possible causes of OBDII code P1118 in a 2008 Toyota Prius include a faulty coolant temperature sensor, issues with the coolant temperature sensor circuit, or problems with the coolant heat storage system itself.

4. How can I diagnose the OBDII code P1118 in my 2008 Toyota Prius?

Diagnosing OBDII code P1118 in a 2008 Toyota Prius typically involves using an OBDII scanner to retrieve the code, checking the coolant level and quality, inspecting the coolant temperature sensor and its wiring, and testing the coolant heat storage system.

5. Can I continue driving my 2008 Toyota Prius with OBDII code P1118?

It is not recommended to continue driving your 2008 Toyota Prius with OBDII code P1118, as it can lead to potential engine overheating and damage. It is best to address the issue promptly to prevent further problems.

6. How can I repair OBDII code P1118 in my 2008 Toyota Prius?

Repairing OBDII code P1118 in a 2008 Toyota Prius may involve replacing the faulty coolant temperature sensor, repairing any issues with the sensor circuit, or addressing problems with the coolant heat storage system. It is advisable to consult with a professional mechanic for an accurate diagnosis and repair.

7. Is OBDII code P1118 a serious issue in a 2008 Toyota Prius?

OBDII code P1118 should be addressed promptly in a 2008 Toyota Prius to prevent potential engine overheating and damage. While it may not always cause immediate harm, it is essential to have the issue diagnosed and repaired to maintain the vehicle's performance and reliability.

8. Can a DIY enthusiast fix OBDII code P1118 in a 2008 Toyota Prius?

While some DIY enthusiasts may have the skills to address OBDII code P1118 in a 2008 Toyota Prius, it is recommended to seek professional assistance, especially when dealing with coolant system components and electrical circuits. Proper diagnosis and repair are crucial to ensure the issue is resolved correctly.

9. How long does it typically take to repair OBDII code P1118 in a 2008 Toyota Prius?

The time to repair OBDII code P1118 in a 2008 Toyota Prius can vary depending on the exact cause of the issue and the extent of the repairs needed. It is advisable to consult with a mechanic for a more accurate estimate of the repair time.

10. Can OBDII code P1118 in a 2008 Toyota Prius affect the vehicle's overall performance?

Yes, OBDII code P1118 in a 2008 Toyota Prius can potentially affect the vehicle's overall performance by causing engine overheating, decreased fuel efficiency, and potential drivability issues. Addressing the code promptly is essential to maintain optimal performance.

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