The intake air temperature (IAT) sensor plays an important role in ensuring the engine runs efficiently and smoothly. It measures the temperature of the air passing out of the air intake system into the engine. The sensor converts its readings into a voltage signal for the powertrain control module (PCM), which uses the data to adjust the amount of fuel that the injectors spray into the cylinders.
The PCM will log a P2199 code if it detects a large discrepancy between the voltage signals sent by different IAT sensors.
The diagnostic trouble code (DTC) P2199 indicates “Intake Air Temperature Sensor 1/2 Correlation.”
Vehicles have more than one intake air temperature sensor, and their location may vary depending on the vehicle’s manufacturer. Most IAT sensors can be found in the air intake pipe or air filter housing. A different design is built into the housing of the mass air flow sensor.
No matter the particular design, most IAT sensors have a thermal resistor that juts into the air inlet. Intake air flows across the resistor.
Higher temperatures lower the resistor’s electrical resistance, which makes the circuit’s voltage rise. Conversely, lower temperatures increase the resistance of the IAT sensor. This lowers the voltage in the circuit.
The PCM interprets these changes in signal voltage as shifts in the temperature of the intake air. It adjusts the fuel intake to compensate for cold or hot air.
Furthermore, the PCM regularly compares the voltage signals sent by the IAT sensors to make sure both devices are working. If the discrepancies between the two signals exceed the maximum threshold, the PCM will set the generic code P2199.
Note: The definition of code P2199 can differ according to the vehicle manufacturer. Check the appropriate repair manual or repair database for the exact code definition.
The P2199 code is a generic code that can register on vehicles of various makes and models. Its causes and symptoms can vary between vehicles, so there isn’t a single diagnostic approach that will work for every instance of the trouble code.
You can run diagnostic tests on the intake air temperature sensor if you have the relevant experience and tools to perform DIY auto repair. Otherwise, it’s recommended to bring your vehicle to a professional mechanic.
To fix the P2199 code yourself, you will need appropriate tools and knowledge in DIY car repair. Not everyone has both, so they generally bring their vehicle to an auto service center they trust.
For DIYers with advanced technical knowledge and hands-on experience who prefer to test and replace their vehicle’s IAT sensor on their own, it’s a good idea to consult the relevant repair manual or check an online repair database.
Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.