AutoCodes – Toyota – P1117 2008 Toyota Prius

P1117 2008 Toyota Prius Code - Coolant Temperature Sensor Circuit Stack 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: P1117 2008 Toyota Prius indicates Coolant Temperature Sensor Circuit Stack 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 3,557

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Apr 22, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1117 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 P1117 2008 Toyota Prius - Coolant Temperature Sensor Circuit Stack for Coolant Heat Storage System - AutoCodes.com — P1117 2008 Toyota Prius Code - Coolant Temperature Sensor Circuit Stack for Coolant Heat Storage System

What does this mean?

What are the Possible Causes of the DTC P1117 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 P1117 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 P1117 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 P1117 2008 Toyota Prius code?

Need more information on how to fix the P1117 2008 Toyota Prius code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P1117 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 P1117 2008 Toyota Prius Code

1. What does the OBDII code P1117 mean on a 2008 Toyota Prius?

P1117 refers to a malfunction in the coolant temperature sensor circuit for the Coolant Heat Storage (CHS) system, indicating an issue with the sensor's signal or wiring.

2. What are the common symptoms of code P1117 in a Toyota Prius?

Symptoms may include the check engine light turning on, reduced fuel efficiency, difficulty maintaining engine temperature, or the CHS system not functioning properly.

3. What causes the P1117 code to appear on a 2008 Toyota Prius?

Common causes include a faulty coolant temperature sensor, damaged wiring or connectors in the sensor circuit, or issues with the engine control module (ECM).

4. How do I diagnose the P1117 code on my Toyota Prius?

Start by checking the coolant temperature sensor and its wiring for damage or corrosion. Use a multimeter to test the sensor's resistance and verify proper voltage within the circuit.

5. Can a faulty coolant temperature sensor cause engine performance issues?

Yes, a malfunctioning sensor can lead to improper engine temperature regulation, which may affect fuel efficiency and overall engine performance.

6. How do I fix the P1117 code on a 2008 Toyota Prius?

Repairs typically involve replacing the coolant temperature sensor if it's faulty, repairing damaged wiring or connectors, or, in rare cases, reprogramming or replacing the ECM.

7. Is it safe to drive with the P1117 code active?

While the car may still be drivable, ignoring this code can lead to reduced fuel efficiency and potential long-term damage to the engine or cooling system.

8. How much does it cost to repair the P1117 code on a Toyota Prius?

Replacing the coolant temperature sensor typically costs between $100 and $300, including parts and labor. Additional costs may apply if wiring or other components need repair.

9. Can low coolant levels trigger the P1117 code?

Low coolant levels themselves may not directly cause this code, but they can lead to overheating or other issues that may indirectly affect the coolant heat storage system.

10. Do I need specialized tools to fix the P1117 code?

Basic tools like a multimeter and an OBDII scanner are typically enough for diagnosing and repairing this issue. A repair manual for the 2008 Toyota Prius may also be helpful.

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