Intake Air Temperature Sensor 1/2 Correlation
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.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- moderate
- Estimated cost
- $30 - $200 (parts and labor)
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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
-
Compare readings of both IAT sensors with a scan tool at cold start -- they should match ambient temperature
-
Inspect wiring and connectors for both IAT sensors
-
Check for intake air leaks near either sensor location
-
Swap the two sensors if accessible and see if the correlation error shifts
-
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.
Sources
This page is built from documented references. Verify against your own service info before repair work.
P2199 on Diesel, EV & Equipment
The same code ID appears across other engines and platforms. The diagnostic flow varies by manufacturer — these are the platform-specific breakdowns:
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