AutoCodes – GMC – P0111 2018 GMC Sierra

P0111 2018 GMC Sierra Code - Intake Air Temperature Circuit Range/Performance Problem

Quick Answer

The Intake Air Temperature (IAT) sensor 1 is a variable resistor that changes the voltage on the Engine Control Module (ECM) supplied 5 V signal circuit. Common causes include Faulty Intake Air Temperature (IAT) sensor, Intake Air Temperature sensor harness is open or shorted, Intake Air Temperature sensor circuit poor electrical connection. 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: P0111 2018 GMC Sierra indicates Intake Air Temperature Circuit Range/Performance Problem.
Common causes: Common causes include Faulty Intake Air Temperature (IAT) sensor, Intake Air Temperature sensor harness is open or shorted, Intake Air Temperature sensor circuit poor electrical connection.
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 220

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 May 16, 2022

Description
Possible Causes
How To Fix
Tech Notes ▶
Cost to Diagnose
FAQs
Comments
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Code P0111 2018 GMC Sierra Description

The Intake Air Temperature (IAT) sensor 1 is a variable resistor that changes the voltage on the Engine Control Module (ECM) supplied 5 V signal circuit. The signal varies with inlet air temperature in the sensor bore and is displayed by the scan tool as °C (°F). The IAT sensor 2 and the humidity sensor share the same circuit. The IAT sensor 2 signal is displayed by the scan tool as Hertz (Hz) and °C (°F). The Diagnostic Trouble Code (DTC) will be set when the ECM determines the absolute difference between the IAT sensor 1 start-up temperature and the IAT sensor 2 start-up temperature is greater than 25°C (45°F).

OBDII Code P0111 2018 GMC Sierra - Intake Air Temperature Circuit Range/Performance Problem - AutoCodes.com — P0111 2018 GMC Sierra Code - Intake Air Temperature Circuit Range/Performance Problem

What does this mean?

What are the Possible Causes of the DTC P0111 2018 GMC Sierra?

Faulty Intake Air Temperature (IAT) sensor
Intake Air Temperature sensor harness is open or shorted
Intake Air Temperature sensor circuit poor electrical connection
Faulty Engine Control Module (ECM)

How to Fix the DTC P0111 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 does this mean?

Code Tech Notes

The Intake Air Temperature (IAT) sensor 1, IAT sensor 2, Humidity sensor, MAF sensor, and BARO pressure sensor are integrated within the Mass Air Flow / Multifunction Intake Air Sensor.

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What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0111 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 P0111 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 P0111 2018 GMC Sierra Code

1. What are the common symptoms of OBDII code P0111 in a 2018 GMC Sierra?

- Common symptoms include poor engine performance, rough idling, decreased fuel efficiency, and potential stalling.

2. What does the OBDII code P0111 for a 2018 GMC Sierra indicate?

- The code P0111 indicates an issue with the Intake Air Temperature (IAT) sensor circuit, specifically a range/performance problem.

3. What are the possible causes of the P0111 code in a 2018 GMC Sierra?

- Potential causes include a faulty IAT sensor, damaged wiring or connectors in the IAT circuit, or a problem with the engine control module (ECM).

4. How can I diagnose the P0111 code in my 2018 GMC Sierra?

- To diagnose the issue, you can use an OBDII scanner to read the code and check the IAT sensor's resistance, inspect the wiring for damage, and test the ECM's functionality.

5. Can a dirty air filter trigger the P0111 code in a 2018 GMC Sierra?

- While a dirty air filter doesn't directly cause the P0111 code, it can affect the overall engine performance, potentially leading to issues that trigger the code.

6. How can I repair the Intake Air Temperature Circuit Range/Performance Problem in a 2018 GMC Sierra?

- Repair options include replacing the faulty IAT sensor, repairing or replacing damaged wiring, and resetting the ECM to clear the code.

7. Is it safe to continue driving with the P0111 code illuminated in a 2018 GMC Sierra?

- It is not recommended to drive with the P0111 code active, as it can lead to further engine problems and potential damage if left unresolved.

8. Can extreme temperatures affect the IAT sensor and trigger the P0111 code in a 2018 GMC Sierra?

- Yes, extreme temperatures can impact the IAT sensor's readings and potentially trigger the P0111 code if the sensor malfunctions due to temperature variations.

9. How much does it typically cost to repair the P0111 code in a 2018 GMC Sierra?

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

10. Will resetting the OBDII system turn off the P0111 code in a 2018 GMC Sierra?

- Resetting the system may temporarily clear the code, but if the underlying issue is not fixed, the code is likely to reappear after some driving cycles.