Intake Air Temperature Sensor 1/2 Correlation
Code P2199 indicates a mismatch or correlation problem between two intake air temperature (IAT) sensors or their signals. The PCM has detected that the two IAT sensor readings are not correlating as expected, suggesting a fault in one sensor, wiring, or the sensors themselves.
What You Might Notice
- Diminished engine performance
- Reduced fuel efficiency
- Hesitation upon acceleration
- Check engine light illuminated
- Possible rough idle
Most Common Causes
- 1
Defective IAT sensor
One or both intake air temperature sensors are malfunctioning and providing inaccurate signal voltage to the PCM.
- 2
Disconnected or loose IAT sensor
The IAT sensor connector is unplugged, corroded, or not fully seated, causing signal loss or poor electrical contact.
- 3
Open or shorted circuit in IAT wiring
Wiring between the IAT sensors and PCM has an open circuit or short, preventing proper signal transmission.
- 4
Restricted air filter
A clogged air filter can affect intake air temperature readings and cause correlation issues between dual sensors.
How to Diagnose It
- 1
Check Defective IAT sensor — One or both intake air temperature sensors are malfunctioning and providing inaccurate signal voltage to the PCM.
- 2
Check Disconnected or loose IAT sensor — The IAT sensor connector is unplugged, corroded, or not fully seated, causing signal loss or poor electrical contact.
- 3
Check Open or shorted circuit in IAT wiring — Wiring between the IAT sensors and PCM has an open circuit or short, preventing proper signal transmission.
- 4
Check Restricted air filter — A clogged air filter can affect intake air temperature readings and cause correlation issues between dual sensors.
How to Fix It
- 1
Inspect and reconnect IAT sensors
Locate both IAT sensors (typically in or near the air intake), check for disconnection or corrosion, clean connector pins, and ensure proper seating.
- 2
Replace defective IAT sensor
Remove the faulty intake air temperature sensor and install a new OEM or quality replacement sensor, then clear the code and test.
- 3
Repair IAT sensor wiring and connectors
Inspect wiring harness for damage, corrosion, or breaks between the IAT sensors and PCM. Repair or replace damaged sections and ensure all connections are secure.
- 4
Replace air filter and check intake system
Install a new engine air filter to ensure proper airflow and accurate temperature readings. Inspect the intake system for blockages or design issues affecting sensor correlation.
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