GM Vehicle Error Code P1111: How to Fix It

Q: Can I drive with GM error code P1111?

Yes, you can typically drive with P1111 as it's a low-severity code, but you may experience reduced fuel economy, rough idle, or poor engine performance. Address the issue promptly to prevent potential damage to other components.

Q: What causes GM error code P1111 to appear?

P1111 is commonly caused by a faulty IAT sensor, corroded electrical connections, damaged wiring, or contamination on the sensor. Temperature cycling and age can cause the sensor's internal resistance to become unstable.

Q: How much does it cost to fix GM error code P1111?

If the fix involves cleaning connections, the cost is minimal (under $10 for contact cleaner). A replacement IAT sensor typically costs $20-60, while professional diagnosis and repair can range from $100-200 depending on labor rates.

Q: Will P1111 cause my GM vehicle to fail emissions testing?

Yes, P1111 can cause emissions test failure as it affects the engine's air-fuel mixture calculations. The error code must be resolved and the readiness monitors must complete before passing emissions testing.

Q: Is GM error code P1111 the same as P0113?

No, P1111 is a GM-specific code for intermittent IAT sensor high voltage, while P0113 is a generic code for IAT sensor high input. P1111 specifically indicates an intermittent problem rather than a constant high reading.

Abstract

Error code P1111 on GM vehicles indicates an intermittent high voltage reading from the Intake Air Temperature (IAT) sensor. This sensor measures incoming air temperature to help your engine's computer optimize fuel mixture and timing, and when it sends erratic signals, it can affect engine performance and fuel economy.