The intake air temperature (IAT) sensor, otherwise known as the air charge temperature sensor, is used by the powertrain control module (PCM) to determine the temperature (and therefore the density) of air entering the engine. Typically, the PCM sends a 5-volt reference to the IAT sensor. The IAT sensor then varies its internal resistance according to air temperature and sends a return signal back to the PCM. The PCM then uses this formation to determine fuel injector control and other outputs.
A bad IAT sensor can cause all kinds of drivability problems including a rough idle, surging, stalling, and poor fuel economy. To replace this part, you can follow the step-by-step guide below.
Part 1 of 2: Removing the old intake air temperature sensor
In order to safely and efficiently replace your IAT sensor, you will need a couple of basic tools.
- New IAT sensor
- Protective gloves
- Repair manuals (optional) - You can access these through Chilton, or Autozone provides free online repair manuals for certain makes and models.
- Safety glasses
Step 1: Locate the sensor. The IAT sensor is usually located in the air intake boot, but it may also be located in the air cleaner housing or intake manifold.
Step 2: Disconnect the negative battery cable. Disconnect the negative battery cable and set it aside.
Step 3: Remove the sensor’s electrical connector. Now that you know where the IAT sensor is located, you can remove its electrical connector.
Step 4: Remove the sensor. Carefully remove the faulty sensor, keeping in mind that some sensors simply pull straight out while others must be unscrewed using a wrench.
Part 2 of 2: Installing the new intake air temperature sensor
Step 1: Install the new sensor. Install the new sensor by pushing it straight in or screwing it in, depending on the design.
Step 2: Reinstall the electrical connector. To enable the new sensor, you must now reconnect the electrical connector.
Step 3: Reinstall the negative battery cable. As a final step, reinstall the negative battery cable.
As you can see, replacing an intake air temperature sensor is a pretty straightforward process that most can manage with very few materials. Of course, if you’d rather have someone else do the dirty work for you, the team of certified mechanics at YourMechanic offers professional intake air temperature sensor replacement.
This article originally appeared on YourMechanic.com as How to Replace an Intake Air Temperature Sensor and was authored by Mia Bevacqua.