Q: MAP sensor or something else?

asked by on February 24, 2018

After doing some diagnostics on my car with the trouble code PO505, I started with checking the voltage from the PCM to the MAP sensor and that voltage was good. Then I back propped the MAP sensor and cranked up the car. Doing this, I was testing the voltage from the increase of the vacuum when the RPMs increase. I revved the engine up to 2000 RPMs and the voltage went from 1.5 down to 1.35 when it should have increase from the increase of vacuum. Also, I have checked the IAC valve and it seems to be operating like it should.

Does this indicate a bad MAP sensor? or is there any other way I can go about checking before I come to a conclusion.

My car has 164000 miles.
My car has an automatic transmission.

I would recommend using a service such as All data, Mitchell ProDemand, or a Chilton book. The sources may give you the correct testing procedure for the map sensor. By using these test procedures you can be certain that the map sensor has been tested properly.

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