AutoCodes – Mercedes-Benz – P0117 Mercedes-Benz

P0117 Mercedes-Benz 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 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: P0117 Mercedes-Benz indicates Engine Coolant Temperature Circuit Low Input.
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.

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Code Popularity 18,362

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 Sep 07, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0117 Mercedes-Benz 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 that is sensitive to the change in temperature. The electrical resistance of the thermistor decreases as temperature increases. The Diagnostic Trouble Code (DTC) will be set when an excessively low voltage from the sensor is sent to ECM.

OBDII Code P0117 Mercedes-Benz - Engine Coolant Temperature Circuit Low Input - AutoCodes.com — P0117 Mercedes-Benz Code - Engine Coolant Temperature Circuit Low Input

What does this mean?

What are the Possible Causes of the DTC P0117 Mercedes-Benz?

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

How to Fix the DTC P0117 Mercedes-Benz?

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 P0117 Mercedes-Benz 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 Mercedes-Benz code?

Need more information on how to fix the P0117 Mercedes-Benz code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0117 Mercedes-Benz 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 P0117 Mercedes-Benz Code

1. What are the common symptoms of OBDII code P0117 in a Mercedes-Benz?

- Common symptoms include inaccurate temperature gauge readings, overheating, poor fuel economy, and potential engine misfires.

2. What causes the OBDII code P0117 in a Mercedes-Benz?

- The code P0117 is triggered when the Engine Control Module (ECM) detects a low input signal from the engine coolant temperature sensor.

3. How can I diagnose the OBDII code P0117 in my Mercedes-Benz?

- Diagnosing the code involves checking the engine coolant temperature sensor for proper operation, inspecting the wiring for any damage, and verifying the coolant levels.

4. Can a faulty thermostat cause the OBDII code P0117 in a Mercedes-Benz?

- Yes, a faulty thermostat can sometimes cause erroneous temperature readings, leading to the triggering of code P0117.

5. What are some repair tips for resolving the OBDII code P0117 in a Mercedes-Benz?

- Repair tips include replacing the engine coolant temperature sensor, checking and repairing any damaged wiring, and ensuring proper cooling system operation.

6. Is it safe to drive my Mercedes-Benz with the OBDII code P0117?

- It is not recommended to drive with the code active, as it can lead to potential engine overheating and other issues. Immediate diagnosis and repair are advisable.

7. Can a DIY enthusiast fix the OBDII code P0117 in a Mercedes-Benz?

- While some basic diagnostics can be done by DIY enthusiasts, resolving the code may require specialized tools and expertise, so professional assistance is recommended.

8. How much does it typically cost to repair the OBDII code P0117 in a Mercedes-Benz?

- The cost of repair can vary depending on the exact cause of the issue, but it may range from around $100 to $300 for parts and labor.

9. Will resetting the OBDII code P0117 in a Mercedes-Benz make it go away permanently?

- Resetting the code without addressing the underlying issue will not fix the problem permanently. The root cause should be diagnosed and repaired to prevent the code from reoccurring.

10. How long does it take to repair the OBDII code P0117 in a Mercedes-Benz?

- The repair time can vary based on the specific diagnosis and the extent of the repair needed, but it typically takes a few hours to complete the repair.