where is IAT sensor located on dodge diesel 3500?

The MAP and IAT are in combination on the intake manifold/plenum cover plate.
Its called a "combo" sensor.the IAT is mounted on top on the output side of the air cleaner held by two torx screws. Tha maf is located on the engine next to the air intake manifold. It can get dirty from runnning oiled air cleaners.Be careful not to confuse the "combo" sensor with the "combo" sensor on the airbox. They are similar but different.

REMOVAL

The combination, dual function Intake Manifold Air temperature sensor/MAP (IAT/MAP) sensor is installed into the top of the intake manifold (see picture).

1. Clean area around sensor.
2. Disconnect electrical connector from IAT/MAP sensor.
3. Remove two T-15 Torx headed screws.
4. Remove sensor from intake manifold.
5. Check condition of sensor o-ring

INSTALLATION

1. Check condition of sensor o-ring.
2. Lubricate sensor o-ring with clean engine oil.
3. Clean sensor mounting area at intake manifold.
4. Position sensor into intake manifold.
5. Install and tighten 2 sensor mounting screws to 1 N·m (9 in. lbs.) torque.
6. Connect electrical connector to sensor.

7. Right click on the image and select option "open image in new web" if the image is not seen full or its very small to see.-----------

Right click on the image and select option "open image in new web" if the image is not seen full or its very small to see.-----------

1 - TOP OF INTAKE MANIFOLD

2 - IAT/MAP SENSOR

3 - ELEC. CONNECTOR

4 - MOUNTING BOLTS (2)