AutoCodes – GMC – P0218 GMC

P0218 GMC 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 GMC 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 5,481

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
Comments
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Code P0218 GMC 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 GMC - Transmission Fluid Overtemperature - AutoCodes.com — P0218 GMC Code - Transmission Fluid Overtemperature

What does this mean?

What are the Possible Causes of the DTC P0218 GMC?

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 GMC?

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 GMC 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 GMC code?

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Need Help with the Code?

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Information for Specific GMC Models

P0218 2014 GMC Sierra — Transmission Fluid Overtemperature
P0218 2015 GMC Sierra — Transmission Fluid Overtemperature
P0218 2016 GMC Sierra — Transmission Fluid Overtemperature
P0218 2017 GMC Sierra — Transmission Fluid Overtemperature
P0218 2018 GMC Sierra — Transmission Fluid Overtemperature

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.