MAP (Manifold Atmosphere Pressure) Sensor
The MAP sensor is installed into the rear of the intake manifold. The MAP sensor reacts to air pressure changes in the intake manifold. It provides an input voltage to the Engine Control Module (ECM). As pressure changes, MAP sensor voltage will change. The change in MAP sensor voltage results in a different input voltage to the ECM. The ECM uses this input, along with inputs from other sensors to provide fuel timing, fuel control and engine protection. Engine protection is used to derate (drop power off) the engine if turbocharger pressure becomes to high.
Mopar's Notes: This cleaning procedure will not correct any error codes that are being produced by the MAP sensor (P0237 or P0238). If you got a fueling enhancement box of any type hooked to the MAP sensor lines it could be a internal fault of the boost fooler circuit causing the MAP sensor error code. If the truck is stock then the MAP sensor requires replacement.
This cleaning process is normally for Dodge Cummins that have exhaust brakes installed. But there has be a few reports of MAP sensors being dirty without a exhaust brake install. There is no maintenance schedule for cleaning the MAP sensor. If you do have a exhaust brake I suggest every oil change you clean the sensor. I clean mine every 6,000 miles and do a oil change at the same time.
Ok. first thing when need to know is where is the MAP sensor located at. It's on the driver side of the engine just passed the fuel filter.
Now you need the proper tool to remove it. You need a 1-1/16" deep well socket to remove the MAP sensor. Also your going to need a 3" extension. Preferably 1/2" drive.
Mopar's Notes: It could also be a 1 1/4" socket too.
Here is what the sensor looks like when its dirty. Now all you got to do is give it a few sprays of carburetor cleaner to remove the oily coating.
Now that they are cleaned. Just reverse the process to install them back in the manifold.