AutoCodes – Toyota – P1115 2008 Toyota Prius

P1115 2008 Toyota Prius Code - Coolant Temperature Sensor Circuit For 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: P1115 2008 Toyota Prius indicates Coolant Temperature Sensor Circuit For 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 3,316

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 21, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1115 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 P1115 2008 Toyota Prius - Coolant Temperature Sensor Circuit For Heat Storage System - AutoCodes.com — P1115 2008 Toyota Prius Code - Coolant Temperature Sensor Circuit For Heat Storage System

What does this mean?

What are the Possible Causes of the DTC P1115 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 P1115 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 P1115 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 P1115 2008 Toyota Prius code?

Need more information on how to fix the P1115 2008 Toyota Prius code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P1115 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 P1115 2008 Toyota Prius Code

1. What does OBDII code P1115 mean for a 2008 Toyota Prius?

Code P1115 indicates an issue with the Coolant Temperature Sensor Circuit for the Heat Storage System, which monitors and manages engine coolant temperature in the heat storage tank.

2. What are the common symptoms of code P1115 in a 2008 Toyota Prius?

Symptoms include the check engine light turning on, poor fuel efficiency, longer engine warm-up times, and potential overheating or cooling system irregularities.

3. What causes code P1115 to appear on a 2008 Toyota Prius?

Common causes include a faulty coolant temperature sensor, damaged wiring or connectors, a malfunctioning heat storage tank, or issues with the engine control module (ECM).

4. How do you diagnose OBDII code P1115 in a 2008 Toyota Prius?

Diagnosis involves checking the sensor wiring and connectors for damage, testing the coolant temperature sensor for proper resistance, and using a scan tool to monitor live data from the heat storage system.

5. Can I drive my 2008 Toyota Prius with code P1115?

While the car may still be drivable, itâ€™s not recommended, as the issue can lead to poor engine performance or potential overheating if not resolved promptly.

6. How do you fix code P1115 on a 2008 Toyota Prius?

Repairs may include replacing the coolant temperature sensor, repairing or replacing damaged wiring or connectors, or addressing issues within the heat storage system.

7. How much does it cost to fix code P1115 on a 2008 Toyota Prius?

Depending on the exact issue, repairs can range from $100 to $300 for parts and labor, with higher costs if the heat storage system itself requires replacement.

8. Can a low coolant level trigger code P1115 in a 2008 Toyota Prius?

Yes, low coolant levels can affect the heat storage systemâ€™s operation and cause erratic temperature readings, which may trigger the code.

9. Does code P1115 affect the hybrid system in a 2008 Toyota Prius?

While primarily related to the cooling system, unresolved issues could indirectly affect the hybrid systemâ€™s efficiency by causing the engine to run less efficiently.

10. Is code P1115 common in 2008 Toyota Prius vehicles?

While not exceedingly common, this code can occur due to the Priusâ€™s reliance on an advanced cooling system with a heat storage tank, making sensor and wiring issues more noticeable.

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