02 kobelco 210 dynamic acera engine pull down pump vibration p2 nega con

[dcf70]

have a kobelco 210 that has a (( "b 12 se" p2 nega con sensor)) that started coming and going lately and at same time frame engine pulls down on idle like pump is still engaged with or without pilot lock on off (lever by seat for pilot control system)
the first time happened was after running for couple hours and started blowing black smoke like was major pull down
anyone had this code or symptoms that can point me in right direction to test ports and what not
THANKS IN ADVANCE!!!

 

[Kyle Helmke]

the nega con sensors are for the control pressure to the pumps from the control valve. they control when the pumps come on stroke. That code indicates there is an issue most likey with the sensor or possibly wiring. the p2 pump is the farthest away from the engine. the nega sensor will be the one on the regulator. I would swap the wires from p1 nega con with p2 nega con. if the code changes to p1 then your sensor is bad or you have an actual pressure issue, if it does not change then you have a wiring issue and you need to check your harness where it runs through the metal bend over tabs is usually where they get damaged

 

[dcf70]

thanks so basically that tells pump to go into higher flow mode and could cause the vibration and stalling of engine if its telling pump to be kicked in even with pilot controll lever off??

 

[Kyle Helmke]

yes a failing nega sensor can cause the pump to load up even when your not requesting it because it thinks you are

 

[dcf70]

thanks again ill switch wiring tomorrow and see what does.. sensor warning dont stay on all time is biggest problem so hopefully is when try in morning.. if it is on when start would i be able to swap wiring while running to help without messing something up or better off shutting off and doing it??

 

[Kyle Helmke]

you can swap it running it should clear codes when plugged back in