Intake Air Temperature Sensor 1/2 Correlation
What does P2199 mean?
The P2199 code means the vehicle's onboard diagnostic system has detected: Intake Air Temperature Sensor 1/2 Correlation. This is a low severity code.
Common Symptoms
- Check Engine Light on
- Slightly rough idle when cold
- Minor performance changes
- Inaccurate temperature gauge readings
- Occasional stalling in cold weather
Probable Causes (Ranked by Likelihood)
- Faulty intake air temperature sensor 1 or 2 Very High
- Wiring issue between the two IAT sensors High
- Intake manifold air leak affecting one sensor location Moderate
- Connector corrosion on one of the IAT sensors Moderate
- ECM calibration or software issue Low
Step-by-Step Diagnostic Procedure
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Compare readings of both IAT sensors with a scan tool at cold start -- they should match ambient temperature
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Inspect wiring and connectors for both IAT sensors
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Check for intake air leaks near either sensor location
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Swap the two sensors if accessible and see if the correlation error shifts
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Verify ECM software is up to date
Frequently Asked Questions
What does IAT sensor correlation mean?
Modern vehicles often have two intake air temperature sensors. A correlation code means the readings from the two sensors differ by more than the allowable threshold, indicating one sensor is reading incorrectly.
Is P2199 serious?
P2199 is generally a low-severity code. The engine will still run, but may not optimize fuel delivery as accurately in certain temperature conditions.
Can I replace the IAT sensor myself?
Yes, IAT sensors are typically accessible and relatively inexpensive. Replacing one is usually a matter of unplugging the connector and removing the sensor from the intake tract.