AutoCodes – GMC – P0218 2018 GMC Sierra

P0218 2018 GMC Sierra Code - Transmission Fluid Overtemperature

Quick Answer

The Transmission Fluid Temperature Sensor is a 2-wire sensor located in the pressure switch manifold. Common causes include Low transmission fluid level, Obstructions to the airflow to the radiator or transmission, Radiator damage. 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: P0218 2018 GMC Sierra indicates Transmission Fluid Overtemperature.
Common causes: Common causes include Low transmission fluid level, Obstructions to the airflow to the radiator or transmission, Radiator damage.
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 275

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 Jun 09, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0218 2018 GMC Sierra Description

The Transmission Fluid Temperature Sensor is a 2-wire sensor located in the pressure switch manifold. The Transmission Control Module (TCM) supplies the transmission fluid temperature sensor signal circuit and a low reference circuit. The resistance of the transmission fluid temperature sensor decreases as the oil temperature increases. The TCM monitors the voltage drop across the transmission fluid temperature sensor and calculates the temperature of the transmission fluid in the sump. The Diagnostic Trouble Code (DTC) sets when the transmission sump temperature is 122°C (251°F) or greater for 10 s.

OBDII Code P0218 2018 GMC Sierra - Transmission Fluid Overtemperature - AutoCodes.com — P0218 2018 GMC Sierra Code - Transmission Fluid Overtemperature

What does this mean?

What are the Possible Causes of the DTC P0218 2018 GMC Sierra?

Low transmission fluid level
Obstructions to the airflow to the radiator or transmission
Radiator damage
Transmission cooling system concerns

How to Fix the DTC P0218 2018 GMC Sierra?

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 P0218 2018 GMC Sierra 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 P0218 2018 GMC Sierra code?

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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 P0218 2018 GMC Sierra Code

1. What does OBDII code P0218 mean on a 2018 GMC Sierra?

- OBDII code P0218 indicates Transmission Fluid Overtemperature on a 2018 GMC Sierra.

2. What are common symptoms of OBDII code P0218 on a 2018 GMC Sierra?

- Common symptoms of P0218 may include the transmission overheating warning light illuminating on the dashboard, transmission slipping, or the vehicle going into limp mode.

3. What are the possible causes of OBDII code P0218 on a 2018 GMC Sierra?

- Potential causes of P0218 include low transmission fluid levels, a faulty transmission fluid temperature sensor, a malfunctioning cooling system, or a clogged transmission fluid cooler.

4. How can I diagnose OBDII code P0218 on my 2018 GMC Sierra?

- To diagnose P0218, you can use an OBDII scanner to read the code, check the transmission fluid level and condition, inspect the transmission fluid temperature sensor, and verify the cooling system's functionality.

5. Can driving with OBDII code P0218 on a 2018 GMC Sierra damage the transmission?

- Driving with P0218 can potentially damage the transmission due to overheating, so it is recommended to address the issue promptly to prevent further damage.

6. How should I repair OBDII code P0218 on my 2018 GMC Sierra?

- Repairing P0218 may involve checking and topping up the transmission fluid, replacing the transmission fluid temperature sensor, flushing the transmission fluid, or repairing/replacing the cooling system components.

7. Is it safe to continue driving my 2018 GMC Sierra with OBDII code P0218?

- It is not recommended to continue driving the vehicle with P0218 as it can lead to transmission damage. It is best to address the issue and have the vehicle inspected by a professional.

8. Are there any preventive maintenance tips to avoid OBDII code P0218 on a 2018 GMC Sierra?

- To prevent P0218, ensure regular transmission fluid checks and changes as per the manufacturer's recommendations, maintain the cooling system in good condition, and address any overheating issues promptly.

9. Can a DIY enthusiast fix OBDII code P0218 on a 2018 GMC Sierra?

- Depending on the underlying cause, some DIY enthusiasts may be able to address P0218 by checking and topping up transmission fluid or replacing the transmission fluid temperature sensor. However, more complex issues may require professional assistance.

10. How much does it typically cost to repair OBDII code P0218 on a 2018 GMC Sierra?

- The cost to repair P0218 can vary based on the specific cause and needed repairs. Costs may range from a simple fluid top-up to sensor replacement or cooling system repairs, potentially costing a few hundred to over a thousand dollars.