Engine-CodesGMC – P1111 GMC

P1111 GMC Code - Intake Air Temperature Sensor Circuit Intermittent High Voltage

Quick Answer

The P1111 GMC code indicates that there is an issue with the Intake Air Temperature (IAT) Sensor Circuit in the vehicle, specifically detecting intermittent high voltage. Common causes include Faulty IAT sensor, Damaged wiring or connectors in the sensor circuit, ECM malfunction. 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
P1111 GMC indicates Intake Air Temperature Sensor Circuit Intermittent High Voltage.
Common causes
Common causes include Faulty IAT sensor, Damaged wiring or connectors in the sensor circuit, ECM malfunction.
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.
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 P1111 GMC Description

The P1111 GMC code indicates that there is an issue with the Intake Air Temperature (IAT) Sensor Circuit in the vehicle, specifically detecting intermittent high voltage. The IAT sensor is responsible for measuring the temperature of the air entering the engine, which is crucial for determining the air-fuel mixture ratio. When the sensor detects high voltage intermittently, it can disrupt the engine's performance and fuel efficiency.

OBDII Code P1111 GMC - Intake Air Temperature Sensor Circuit Intermittent High Voltage
P1111 GMC Code - Intake Air Temperature Sensor Circuit Intermittent High Voltage

Common Causes of P1111 GMC

  1. Faulty IAT sensor
  2. Damaged wiring or connectors in the sensor circuit
  3. ECM malfunction
  4. Intake air leaks
  5. Incorrect sensor installation or calibration

Symptoms of P1111 GMC

  1. Decreased fuel efficiency
  2. Engine misfires or rough idling
  3. Check Engine Light illuminated
  4. Reduced engine performance
  5. Emission control issues

How to Fix P1111 GMC

  1. Begin by conducting a thorough diagnostic scan to confirm the P1111 code and identify the specific cause of the high voltage readings.
  2. Inspect the IAT sensor, wiring, and connectors for any visible damage or corrosion. Replace any faulty components as needed.
  3. Test the sensor's resistance and voltage output to ensure it is functioning within the manufacturer's specifications.
  4. Clear the trouble codes from the ECM's memory and perform a test drive to verify that the issue has been resolved.
  5. If the problem persists, consider consulting a professional mechanic for further diagnosis and potential ECM reprogramming or replacement.

Cost to Fix P1111 GMC

The typical repair costs for addressing a P1111 GMC code related to the Intake Air Temperature Sensor Circuit Intermittent High Voltage can vary depending on the specific cause of the issue. In general, the cost of replacing a faulty IAT sensor can range from $50 to $150, while addressing wiring or connector issues may cost between $100 and $200. Additional labor costs can vary based on the complexity of the repair and the rates charged by auto repair shops.

Tech Notes for P1111 GMC

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.

Need more information about the P1111 GMC code?

Need more information on how to fix the P1111 GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P1111 GMC code diagnosed by a professional: Find a repair shop in your area

Information for Specific GMC Models

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 P1111 GMC Code

What does the OBDII code P1111 mean for a GMC vehicle?

Code P1111 indicates an issue with the Intake Air Temperature (IAT) sensor circuit, specifically intermittent high voltage, which may affect engine performance.

What are the common symptoms of code P1111 in a GMC?

Symptoms may include poor engine performance, reduced fuel economy, difficulty starting, or the check engine light turning on.

What causes the P1111 code to appear?

Common causes include a faulty IAT sensor, damaged or corroded wiring, loose electrical connections, or issues with the vehicle’s engine control module (ECM).

Can I drive my GMC with the P1111 code active?

It’s possible to drive the vehicle, but doing so may result in reduced performance or potential damage to engine components if left unresolved.

How can I diagnose the P1111 code in my GMC?

Diagnosis involves inspecting the IAT sensor, checking wiring and connectors for damage, and using a multimeter to test for proper voltage and resistance.

What tools do I need to fix the P1111 code?

You may need an OBDII scanner, a digital multimeter, and basic hand tools to inspect and repair wiring or replace the IAT sensor.

How do I fix the P1111 code on my GMC?

Common fixes include replacing the IAT sensor, repairing damaged wiring, reconnecting loose connectors, or updating/reprogramming the ECM if necessary.

Is a faulty IAT sensor the only reason for the P1111 code?

No, other potential reasons include wiring issues, corroded connectors, or ECM malfunctions.

How much does it cost to repair the P1111 code?

The cost depends on the specific issue, but replacing the IAT sensor typically costs $50-$200, excluding labor if performed by a mechanic.

Will clearing the P1111 code with a scanner fix the problem?

Clearing the code may turn off the check engine light temporarily, but the underlying issue must be resolved to prevent the code from returning.

Discuss the causes and fixes for P1111 GMC OBDII Code

Code P1111 GMC comments

No comments found for this page.