P1111 GMC Code - Intake Air Temperature Sensor Circuit Intermittent High Voltage
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 (Integrated within the Mass Air Flow / Multifunction Intake Air 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
- P1111 GMC indicates Intake Air Temperature Sensor Circuit Intermittent High Voltage.
- Common causes
- Common causes include Faulty Intake Air Temperature (IAT) sensor (Integrated within the Mass Air Flow / Multifunction Intake Air 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.
Code P1111 GMC Description
What are the Possible Causes of the DTC P1111 GMC?
- Faulty Intake Air Temperature (IAT) sensor (Integrated within the Mass Air Flow / Multifunction Intake Air 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 P1111 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.
Code Tech Notes
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P1111 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.
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Information for Specific GMC Models
- P1111 2014 GMC Sierra — Intake Air Temperature Sensor Circuit Intermittent High Voltage
- P1111 2015 GMC Sierra — Intake Air Temperature Sensor Circuit Intermittent High Voltage
- P1111 2016 GMC Sierra — Intake Air Temperature Sensor Circuit Intermittent High Voltage
- P1111 2017 GMC Sierra — Intake Air Temperature Sensor Circuit Intermittent High Voltage
- P1111 2018 GMC Sierra — Intake Air Temperature Sensor Circuit Intermittent High Voltage
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
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