Hi all. Just purchased a 590d John Deere excavator. Never dug into much trouble shooting yet but it appears that the auto idle does not work(checked it out and light would come on but previous owner disconnected hoses from engine solenoid and auto idle solenoid. Will be re-connecting these tomorrow). The 2 stage propel does not seem to be working(rabbit and turtle light illuminates but speed does not change). And lastly the mode selector switch is stuck so unaware what “mode” it is in. In the mean time is there anybody that could explain exactly how the different “modes” work. Does it use the throttle to adjust rpm to slow controls or do it adjust flow and pressure on the pump.
The best explanation is in the Operators manual. Screenshot below from the Operator manual. The pump control solenoid valve is powered at the (3) points indicated on the “high maximum“ line. The difference between high maximum and low maximum is approx 10%. FYI, EDIT *The pump control solenoid valve is normally open , the auto idle and economy solenoid valves are normally closed.*
So by the previous owner capping the lines coming from the auto idle and engine solenoid. And manually setting the engine rpm to the highest setting you should be reaching the maximum power level. Am i correct?
Just so we are talking the same language, there are 3 solenoid valves which are auto idle engine speed , economy engine speed and hydraulic pump control which controls the pump “high/ low“ maximum displacement. When powered the hydraulic pump control solenoid valve is designed to drain the hose back to tank to allow the hydraulic pump to reach “high maximum” displacement. If that particular hose is capped ,the hydraulic pump will never reach “high maximum” displacement .
Just the hoses coming from the “auto engine idle” and “economy engine speed” solenoids to the hydraulic cylinders on the throttle actuation lever are capped. The “pump control” solenoid is still connected… Thanks for the info. Im going to be doing some trouble shooting today to figure out why the previous owner had these hoses capped.