Barometric Psi Sensor Help

Helping out an uncle. 2008 Kenworth W900, CAT C15 MXS.

108-3 Barometric Psi Voltage High (26)
Has occured 116 times
In last 194 hours
Summary reads that its reading 15psi diag. and it doesn't change. I'm assuming it has gone to a default by doing this.
It is derating the engine and causing it to hisitate badly when first started until it warmed up...then it will come and go.

I checked around the wiring harness looking to see if I could find an issue. Found some split wires at the coolant diverter valve..but it is functioning. Will be fixing those.

I do not have a manual on this engine. Is there a Barometric Psi Sensor in the intake...or is it getting this reading from another sensor?

Any help would be great appreciated. THanks alot!

 

Okay, from what I can gather...the -3 will probably be an open circuit. Found the sensor by doing some digging on the web. Looks to be behind the fuel filter on the C15.

Will be testing the harness and feed voltage. From what I have read looks like it needs 5volts to run correctly. No more than .5 volt difference when wiggling.

Is there a way to test the sensor without getting a new sensor? What about resistance can that can be checked?? I could not find the ranges. Does anyone know?

From what I can gather seems all others sensors depend on this sensor to get an initial reading....say a standard to start their readings with. Many other sensors use this sensor. Trying learn what I can about it. First time I've run into this.

 

I was wondering when you would pop up. Thanks alot. I found some information on it...but it was about a D10R dozer. I assumed it would be close to that. I'm getting kind of a crash course with these sensors. Seems like there are WAY more wiring problems than anything else. I did happen to find what pins to use on the harness for testing purposes.

So just for my knowledge. What do various pressures do for fuel management? I understand what it does to the weather and how it work...just want to understand what it does in engine management. I did read where an RV got a barometric pressure fault from having high crankcase pressure which was blowing dip stick out of engine. What are the ranges that the sensor reads 15 to 30bars or what?? What is the relationship between the two? One up one down....both up....both down?? Hope I'm not annoying you...just trying to learn how it works, not just how to fix it.

 

Tested it all out...everything seemed fine. Was about to tell him to get a new sensor...as wiring and ECM tested ok. Had a sensor off a known good truck and it worked fine after installing it.

So just because I always do this anyways...I went in and cleaned up the sensor and lubed the gasket and cleaned the connections and viola...it works now. Must have not been making proper contact before. I had to take the connector off the sensor to get my multimeter prongs into the plug..then put it back on. This must be why my connector and wiring test passed.

I ohmed out both sensors on the supply and sensor sides compared to the return line and both sensor ohmed out the same...so until I cleaned it and reconnected it I really didn't see why the sensor would not work.

Glad he asked me to look at it instead of listening to the shop in town...they told him automatically after reading the code to order a new sensor...

Thanks for explaining the sensor to me.