Engine-Codes.com
Engine-Codes – Mercedes-Benz – P0118 Mercedes-Benz

P0118 Mercedes-Benz Code - Engine Coolant Temperature Circuit High Input

Quick Answer

The P0118 code for Mercedes-Benz vehicles indicates a problem with the engine coolant temperature circuit, specifically a high input signal. Common causes include Faulty engine coolant temperature sensor, Wiring issues such as a short or open circuit, Corrosion or loose connections in the coolant temperature sensor circuit. 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 Mercedes-Benz indicates Engine Coolant Temperature Circuit High Input.
Common causes
Common causes include Faulty engine coolant temperature sensor, Wiring issues such as a short or open circuit, Corrosion or loose connections in the coolant temperature sensor circuit.
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.
What is this?
Table of contents Created and updated by William Orellana on Sep 07, 2024
💬 Need more help? Ask Auto Expert for instant answers — it's free!
AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play

Code P0118 Mercedes-Benz Description

The P0118 code for Mercedes-Benz vehicles indicates a problem with the engine coolant temperature circuit, specifically a high input signal. The engine coolant temperature sensor is responsible for monitoring the temperature of the coolant in the engine and sending this information to the engine control module (ECM). The ECM uses this data to adjust fuel delivery and ignition timing to optimize engine performance and fuel efficiency.

OBDII Code P0118 Mercedes-Benz - Engine Coolant Temperature Circuit High Input
P0118 Mercedes-Benz Code - Engine Coolant Temperature Circuit High Input

Common Causes of P0118 Mercedes-Benz

  1. Faulty engine coolant temperature sensor
  2. Wiring issues such as a short or open circuit
  3. Corrosion or loose connections in the coolant temperature sensor circuit
  4. ECM malfunction or software issue
  5. Coolant level or circulation problems

Symptoms of P0118 Mercedes-Benz

  1. Check engine light illuminated on the dashboard
  2. Engine running hotter than usual
  3. Poor fuel economy
  4. Engine misfires or rough idle
  5. Reduced engine power

How to Fix P0118 Mercedes-Benz

  1. Begin by diagnosing the issue with a scan tool to confirm the P0118 code and assess the coolant temperature sensor's readings.
  2. Check the wiring and connections for any signs of damage, corrosion, or loose connections. Repair or replace as needed.
  3. Test the engine coolant temperature sensor using a multimeter to ensure it is functioning correctly. Replace if necessary.
  4. Clear the code from the ECM's memory and test drive the vehicle to confirm that the issue has been resolved.
  5. If the problem persists, further diagnosis may be required to identify any underlying issues with the ECM or coolant system.

Cost to Fix P0118 Mercedes-Benz

The cost of repairing a P0118 engine coolant temperature circuit high input code can vary depending on the cause of the issue and the specific model of the Mercedes-Benz vehicle. On average, the cost of parts for this repair can range from $50 to $200, while labor costs can range from $100 to $300. It's important to note that diagnostic time and labor rates at auto repair shops can vary, so it's recommended to obtain quotes from local shops for a more accurate estimate.

When is the Code Detected?

An excessively high voltage from the sensor is sent to ECM.

Need more information about the P0118 Mercedes-Benz code?

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

Need Help with the Code?

Get the P0118 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 P0118 Mercedes-Benz Code

1. What are common symptoms of OBDII code P0118 in a Mercedes-Benz?

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

2. What are the possible causes of the P0118 code in a Mercedes-Benz?

- Possible causes include a faulty engine coolant temperature sensor, a malfunctioning thermostat, wiring issues, or a problem with the engine control module (ECM).

3. How can I diagnose the cause of the P0118 code in my Mercedes-Benz?

- To diagnose the issue, you can use a scan tool to check the actual coolant temperature readings, visually inspect the sensor and wiring for damage, and test the thermostat for proper operation.

4. Can driving with the P0118 code cause further damage to my Mercedes-Benz?

- Driving with the P0118 code can potentially cause overheating issues, damage to the engine, and reduced fuel efficiency, so it's best to address the issue promptly.

5. How can I reset the P0118 code in my Mercedes-Benz after making repairs?

- You can reset the code using an OBDII scanner or by disconnecting the car's battery for a few minutes to clear the ECM's memory.

6. Is it safe to continue driving my Mercedes-Benz with the P0118 code present?

- It is not recommended to drive with the P0118 code present, as it can lead to engine overheating and potential damage if left unaddressed.

7. Will replacing the engine coolant temperature sensor fix the P0118 code in my Mercedes-Benz?

- In many cases, replacing the faulty engine coolant temperature sensor can resolve the P0118 code, but it's essential to diagnose the issue accurately to ensure a proper fix.

8. Can a DIY enthusiast repair the P0118 code in a Mercedes-Benz?

- Depending on your skill level and access to tools, DIY enthusiasts may be able to address the P0118 code by replacing the coolant temperature sensor or thermostat themselves.

9. How long does it typically take to repair the P0118 code in a Mercedes-Benz?

- The repair time can vary depending on the exact cause of the P0118 code, but it generally takes between 1 to 2 hours for a professional mechanic to diagnose and fix the issue.

10. Are there any preventive maintenance tips to avoid the P0118 code in a Mercedes-Benz?

- Regularly checking the coolant level, performing cooling system inspections, and replacing the thermostat as recommended can help prevent issues leading to the P0118 code.

Discuss the causes and fixes for P0118 Mercedes-Benz OBDII Code

Submit a New Comment