AutoCodes – Generic – P0118

P0118 Code - Engine Coolant Temperature Sensor Circuit High

Quick Answer

The engine coolant temperature sensor is used to monitor the engine coolant temperature. Common causes include Low engine coolant level, Faulty Engine Coolant Thermostat, Faulty Engine Coolant Temperature (ECT) sensor. 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: P0118 indicates Engine Coolant Temperature Sensor Circuit High.
Common causes: Common causes include Low engine coolant level, Faulty Engine Coolant Thermostat, Faulty Engine Coolant Temperature (ECT) sensor.
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.

Save to My Repairs Step-by-Step Diagnostic Guide My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 89,227

How popular is this code, among other codes? Medium

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 Aug 23, 2022

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes ▶
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P0118 Description

The engine coolant temperature sensor is used to monitor the engine coolant temperature. The engine coolant temperature sensor has a thermistor with a resistance that varies according to the temperature of the engine coolant. When the coolant temperature is low, the resistance in the thermistor increases. When the temperature is high, the resistance drops. These variations in resistance are reflected in the output voltage from the sensor. The Engine Control Module (ECM) monitors the sensor voltage and uses this value to calculate the engine coolant temperature. When the sensor output voltage deviates from the normal operating range, the ECM interprets this as a fault in the engine coolant temperature sensor circuit and stores a Diagnostic Trouble Code (DTC).

OBDII Code P0118 - Engine Coolant Temperature Sensor Circuit High - AutoCodes.com — P0118 Code - Engine Coolant Temperature Sensor Circuit High

What does this mean?

What are the Possible Causes of the DTC P0118?

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

How to Fix the DTC P0118?

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

Start by checking the engine coolant level at the coolant reservoir, a low level may indicate a coolant leak. If the coolant level is correct, you should replace the Engine Coolant Temperature (ECT) sensor to fix the problem. The Engine Coolant Thermostat must be replaced every time there is a repair with the coolant system.

User Submitted Video

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0118 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 P0118 code?

Need more information on how to fix the P0118 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0118 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P0118 Acura — Engine Coolant Temperature Sensor 1 Circuit High Voltage
P0118 Audi — Engine Coolant Temperature Circuit High
P0118 BMW — Engine Coolant Temperature Sensor 1 Circuit High
P0118 Buick — Engine Coolant Temperature Circuit High Input
P0118 Cadillac — Engine Coolant Temperature Circuit High Input
P0118 Chevrolet — Engine Coolant Temperature Circuit High Input
P0118 Chrysler — Engine Coolant Temperature Sensor Circuit High
P0118 Dodge — Engine Coolant Temperature Sensor Circuit High
P0118 Ford — Engine Coolant Temperature Sensor 1 Circuit High
P0118 GMC — Engine Coolant Temperature Circuit High Input
P0118 Honda — Engine Coolant Temperature Sensor 1 Circuit High Voltage
P0118 Hyundai — Engine Coolant Temperature Circuit High Input
P0118 Infiniti — Engine Coolant Temperature Sensor Circuit High
P0118 Isuzu — Engine Coolant Temperature Sensor 1 Circuit High Voltage
P0118 Jaguar — Engine Coolant Temperature Circuit High Input
P0118 Jeep — Engine Coolant Temperature Sensor Circuit High
P0118 KIA — Engine Coolant Temperature Sensor 1 Circuit High Input
P0118 Lexus — Engine Coolant Temperature Circuit High Input
P0118 Lincoln — Engine Coolant Temperature Sensor 1 Circuit High
P0118 Mazda — Engine Coolant Temperature Circuit High Input
P0118 Mercedes-Benz — Engine Coolant Temperature Circuit High Input
P0118 Mercury — Engine Coolant Temperature Sensor 1 Circuit High
P0118 MINI — Engine Coolant Temperature Sensor 1 Circuit High
P0118 Mitsubishi — Engine Coolant Temperature Sensor High Input
P0118 Nissan — Engine Coolant Temperature Sensor Circuit High
P0118 Pontiac — Engine Coolant Temperature Circuit High Input
P0118 RAM — Engine Coolant Temperature Sensor Circuit High
P0118 Saturn — Engine Coolant Temperature Circuit High Input
P0118 Scion — Engine Coolant Temperature Circuit High Input
P0118 Subaru — Engine Coolant Temperature Circuit High Input
P0118 Toyota — Engine Coolant Temperature Circuit High Input
P0118 Volkswagen — Engine Coolant Temperature Circuit High

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 P0118 Code

1. What are the common symptoms of OBDII code P0118 (Engine Coolant Temperature Sensor Circuit High)?

- Common symptoms include engine overheating, inaccurate temperature gauge readings, poor fuel economy, and potential issues with the vehicle's emissions system.

2. What are the possible causes of the P0118 code?

- The code P0118 can be triggered by a faulty engine coolant temperature sensor, a damaged sensor wiring harness, low coolant levels, or issues with the vehicle's cooling system.

3. How can I diagnose the cause of the P0118 code?

- You can diagnose the cause of the P0118 code by checking the engine coolant level, inspecting the sensor and its wiring for damage, and using a multimeter to test the sensor's resistance and voltage readings.

4. Can I still drive my vehicle with the P0118 code?

- It is not recommended to drive your vehicle with the P0118 code, as it can lead to engine overheating and potential damage. It is best to address the issue promptly.

5. How can I repair the P0118 code?

- Repairing the P0118 code typically involves replacing the faulty engine coolant temperature sensor, repairing or replacing any damaged wiring, and ensuring the cooling system is in good working condition.

6. Will resetting the check engine light resolve the P0118 code?

- Simply resetting the check engine light will not resolve the P0118 code. You need to address the underlying issue causing the code to prevent it from reoccurring.

7. What are some tips to prevent the P0118 code from coming back?

- Regularly maintaining your vehicle's cooling system, checking coolant levels, and promptly addressing any issues with the engine coolant temperature sensor can help prevent the P0118 code from reoccurring.

8. Can a faulty engine coolant temperature sensor cause other problems besides triggering the P0118 code?

- Yes, a faulty engine coolant temperature sensor can cause other issues such as poor engine performance, incorrect fuel mixture, and potential damage to the engine due to overheating.

9. Is it possible to bypass or ignore the P0118 code?

- Bypassing or ignoring the P0118 code is not recommended, as it can lead to more serious issues with your vehicle's engine and emissions system. It is best to address the problem promptly.

10. How much does it typically cost to repair the P0118 code?

- The cost of repairing the P0118 code can vary depending on the cause of the issue, but it generally ranges from $100 to $300 for parts and labor.