I’m trying to figure out why my truck is pulling 1psi at idle/turned off. It is normally 0. And when the truck hits OP temp the “hiss tune” makes the gauge show 2psi. What sensor should I be looking for. I was thinking it was the maf sensor, so I changed that out. And still the same issue. Any ideas?
Boost sensor question
- Thread starter Dm23
- Start date
What does the barometric pressure show in the ECM, and does it match actual barometric pressure? If it does, then you need to change the MAP sensor. MAF sensor measures airflow into the engine and has nothing to do with boost (with the exception of MAF generally increasing with boost).
Like I said earlier, you need to verify the MAP and Baro sensors are reading the same at key on/engine off. You also need to verify the actual barometric pressure where you are located to verify which sensor is reading incorrectly. Since the barometric pressure sensor is built into the ECM, it is likely (and hopefully) not the problem. If you don't have access to a scan tool to verify the readings, you can try throwing a MAP sensor in it to see if it changes the reading. Just to clarify, you have stated twice now you changed the MAF sensor (mass air flow) which measure air flow into the engine and is in the intake pipe between the air filter and the turbo. The sensor I am referring to is the MAP (manifold absolute pressure) which reads manifold pressure (aka boost) and installs in the intake manifold that goes across the top of the engine in front of the turbo.
People like that don't stick around long so we don't worry too much about them