2012 6.7 cumin efi live 5 position cts 2 monitor was getting a p0653 code so after changing the map sensor crank position sensor mass airflow sensor and the iat sensor I now am reading 7.5 psi of boost at idle and the truck seems sluggish when driving any ideas what this could be I'm stumped

 

Shouldn't be any boost at idle.........

 

 

the code is for the 5 volt reference voltage to all the sensors and more that you just listed. This sensor supply circuit provides a 5-Volt supply to the Camshaft Position Sensor, Inlet Air Temperature/Pressure Sensor, Exhaust Pressure Sensor, Fuel Pressure Sensor, Boost Pressure/CAC Temperature, EGR Valve, Fan Clutch Assembly, and Crankcase Pressure Sensor.

Its seems more likely the problem is a short to voltage (or bad pcm) on the common supply wire that feeds all these sensors than every individual sensor going bad at the same time.


remove all pressure sensor connectors for each sensor and measure the 5volt ref circuit...if its over 5.1 volts at key on engine off...there is the problem.

 

 

i was thinking that maybe the better way would be to unplug one sensor and measure the voltage. If its over 5.1, start unplugging the other sensors one at a time, monitoring a return to 5.0 volts.

 

 

Yep. Voltage TO the sensor.