Air intake pressure sensor, how to test?

Does anyone know how to test air intake pressure sensor? Manual says to test the wiring harness side of the coupler to measure the sensor output voltage. Do you have to cut in to wiring insulation and test while the coupler is attached to the sensor? How can you test the sensor output voltage with the coupler disconnected?

You're referring to page 8-80 of the manual? I have never had to check this myself, but the instructions on that page look pretty clear.

Yes, I'm referring to page 8-80. The manual states to pull the coupler and test the wiring harness side of the coupler. Which is not testing the sensor itself at all. I must be missing something.

What voltage did you read when checking the harness side, and what voltage did you read checking the coupler side?

With the key in the on position and the bike not running I was not getting any voltage on the harness side. That was with the coupler disconnected from the sensor. Icouldn't tell if the leads were making contact with the coupler or not. I didn't test the sensor for voltage because when it is disconnected it has no power source. There is no resistance spec for the sensor.

Ventura250r wrote:

With the key in the on position and the bike not running I was not getting any voltage on the harness side. That was with the coupler disconnected  from the sensor. Icouldn't tell if the leads were making contact with the coupler or not. I didn't test the sensor for voltage because when it is disconnected it has no power source. There is no resistance spec for the sensor.

I have had 2 sensors fail in 35K miles.  The latest replacement has a new part number, so hopefully Yamaha has upgraded the part.

Video showing test results with bike running:

https://youtu.be/4tKf2AZUC40

Tests of good and bad sensors with variable vacuum applied:

https://youtu.be/YLKXCD2PJFg

https://youtu.be/qD5Tlb6Cjcg

Love your videos, they have helped a lot of people!