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My Eco boost is running about 10% rich on Bank 1 and I cleaned all my MAF/MAP Sensors. I was wondering though how would you go about testing the 4 pin MAP on top of the manifold? I have 5 volts to the ref wire and 5 volts to the signal when the MAP is disconnected and key is on but engine off. As soon as I connect the MAP the sensor wire goes from 5 V to 2 V instantly.

I heard that you measure these with an Hz setting on your DVOM but I’m getting no frequency at all when testing the sensor with my vacuum pump, but my sensor voltage does drop from the high of 2V to about 0.6V at 25 inHg of vacuum.

Why am I not detecting any frequency since everyone says ford MAPS output a frequency signal? This is with a brand new sensor as well as my old one. I have the black lead back probed into ground of the sensor wire and red test lead back probed going to the signal wire. Should the black lead be on the negative battery terminal instead?
 

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My Eco boost is running about 10% rich on Bank 1 and I cleaned all my MAF/MAP Sensors. I was wondering though how would you go about testing the 4 pin MAP on top of the manifold? I have 5 volts to the ref wire and 5 volts to the signal when the MAP is disconnected and key is on but engine off. As soon as I connect the MAP the sensor wire goes from 5 V to 2 V instantly.

I heard that you measure these with an Hz setting on your DVOM but I’m getting no frequency at all when testing the sensor with my vacuum pump, but my sensor voltage does drop from the high of 2V to about 0.6V at 25 inHg of vacuum.

Why am I not detecting any frequency since everyone says ford MAPS output a frequency signal? This is with a brand new sensor as well as my old one. I have the black lead back probed into ground of the sensor wire and red test lead back probed going to the signal wire. Should the black lead be on the negative battery terminal instead?
What you could do, and how I found out the MAP on my Jeep was reading off, is turn the key on but dont start the engine. Read the MAP in this condition as it should be atmospheric pressure.

Most any cell phone should have a barometric pressure sensor and you should be able to find an app to tell you what the phone sees. Could also check your local weather. Compare to the truck. Either that or compare the MAP to the TIP and Turbo Inlet sensors as they all should be the same with the engine off.

I know atmospheric should be around 800 millibar here and my jeep was reading almost 880. Swapped sensor and it was fine.
 

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Also, the MAPs do not output a frequency, they output a voltage. The ecu inputs 5V and the map will return between ~.5-4.5V depending on the pressure. Its a linear function.

There is also the temperature sensor in the MAP that also returns a voltage. This is why there are 4 pins; a 5V supply, a ground, a MAP output, and a temp output.
 
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