AutoCodes – GMC – P0218 2015 GMC Sierra

P0218 2015 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 2015 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 724

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 2015 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 2015 GMC Sierra - Transmission Fluid Overtemperature - AutoCodes.com — P0218 2015 GMC Sierra Code - Transmission Fluid Overtemperature

What does this mean?

What are the Possible Causes of the DTC P0218 2015 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 2015 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 2015 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 2015 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 2015 GMC Sierra Code

1. What does the OBDII code P0218 mean on a 2015 GMC Sierra?

P0218 indicates that the transmission fluid temperature has exceeded its safe operating range, which can lead to transmission damage if not addressed.

2. What are common symptoms of code P0218 on a 2015 GMC Sierra?

Symptoms include a transmission that slips or shifts erratically, warning lights on the dashboard, overheating engine or transmission, and reduced vehicle performance.

3. What causes code P0218 on a 2015 GMC Sierra?

Common causes include low transmission fluid levels, old or contaminated transmission fluid, a malfunctioning transmission cooler, or excessive towing weight.

4. Can driving with code P0218 damage my 2015 GMC Sierra?

Yes, driving with overheated transmission fluid can cause severe internal damage to the transmission and lead to costly repairs.

5. How can I fix code P0218 on my 2015 GMC Sierra?

Check the transmission fluid level and condition, ensure proper cooling system function, inspect for leaks, and avoid overloading or towing beyond the vehicleâ€™s capacity.

6. Does towing heavy loads cause P0218 on a 2015 GMC Sierra?

Yes, towing loads beyond the manufacturerâ€™s specifications can overheat the transmission fluid and trigger code P0218.

7. How do I check the transmission fluid on a 2015 GMC Sierra?

Locate the transmission dipstick, remove it while the engine is running and warm, wipe it clean, reinsert it, and check for proper fluid level and condition.

8. Can a faulty transmission cooler trigger code P0218 on a 2015 GMC Sierra?

Yes, a malfunctioning transmission cooler can fail to regulate fluid temperature, leading to overheating and setting the code.

9. What should I do if my 2015 GMC Sierra shows code P0218?

Stop driving immediately to prevent damage, inspect the transmission fluid and cooling system, and consult a mechanic if necessary.

10. Is it expensive to repair code P0218 on a 2015 GMC Sierra?

The cost depends on the underlying issue, ranging from a simple transmission fluid change to replacing major components like the transmission cooler or the transmission itself.