Hello everyone I’m working on this machine serial EC150LCC03034 Idles fine both pumps at 500psi but when you move any fuction both pumps jump to 4000psi. Code on dash ER22. I have no MAs going to my power shift solenoid. Followed my wires up to the auto/manual switch 902. I have power in from fuse 10 @ 24v but 3 of my terminals have no power. Anyone delt with this issue? Is it an ECU problem? 24v power in is pin 2, switch one way pin 1,2,3 have power. Switch the other way pin 1,2 have power. I never have power on 4,5,6. Please help! Thanks!
Good day Have you tried switching into manual mode ? kind regards Uffex
Yes I have. It still keeps the pumps at 4000 psi and I still dont have MAs at the power shift valve. However in manual mode it reduces rpms which causes the motor to die out even quicker when you put a load on a fuction.
The pump regulation is known as negative control, with power to the power shift valve may over load the engine. we suggest you measure the output pressure from the power shift valve. If you dead end the bucket for example you only burn one pump the engine if good should easily be able to take the load, suspect that you may be looking for the PWM signal with the wrong device, checking the issue this way will show us what is happening. If the engine cannot take the bucket indicates your engine is the issue not the pump regulation.I will search the library for some instructions that may help and post them to you. Kind regards Uffex
Thanks for your help. I don’t believe the engine is the issue because without even dead heading a fuction, just slightly moving the boom, stick or bucket both pumps jump up to 4000 psi. I believe I should only be seeing maybe 1000 or so psi when I move a fuction. Does this power shift valve send fluid to the de-stroke piston inside of the pump? It seems to me they’re stuck at full stroke that’s why the engine bogs down, because it can’t handle that gpm at 4000 psi.
Powershift with power destrokes the pumps see attached come back if we can help further.
A possibility occurs to me has the small hoses been removed recently?
No I haven’t yet removed the small hose from the power shift to the pump. But I was going to remove it to T a gauge in and check my pressure going into my pump. Should I not?
Yes thats fine, a common issue is when the Pi connections get switched but this was a bum steer sorry, can you explain when the problem began this may help to find the cause, .
Good day HydGuy Please see attached
To begin with 1, 2 & 3 are ground control circuits. 4, 5 & 6 are power circuits. Let's start by restoring power from fuse 10 to pin 5 , that may restore functionality. Your V-ECU doesn't see the voltage transferred via SW902 to S12,15,16 & 18 on V-ECU inputs. You need to look closely where the harness goes through the floor on the right and comes up on the left. There have been abrasion problems when operators leave the seat oscillating and pile garbage and tools behind the seat. Let's establish continuity to the switch and from the switch and to the V-ECU.
I appreciate your feedback. Is it possible this is a different serial number than the diagram shows? I thought about switching the wires around to have power at pin 5 but these have never been changed to my knowledge. So I didnt want to change the wires to the switch in case this accidentally could send too much voltage to my v-ecu. Are you referring to the diagram I posted or looking at one yourself?
I am correct in calling the solenoid with three hoses going to it at the very bottom of the picture the power shift solenoid right? This is the one I have no MAs to.
She's an old girl, I honestly don't recall. You'd have to look for wire markers or identifiers. Your machine is still mostly Samsung. Look at IN02-S 14 that will be power out to solenoid MA 902. I say solenoid cuz Volvo is very picky about separating pwm from ma. The return or ground is black w/ red tracer that goes back to SW902, through SW902 to either pin 1 or 3 . I really believe you will have to restore power from FU 10 , verify power at ECU INO3S-12, INO4S-16,18. Until the V-ECU knows what's going on, things will not cooperate. I think you were on the right track in the first place, stay the course. Once you have everything electrically squared away, then go looking for gremlins.
I can confirm that is the Power Shift valve please be aware even with a dead Power Shift valve the engine overload when dead ending the bucket should not occur, do you have fuel issues on the job site with other machines? If you are not convinced connect pilot pressure to the two regulators. KR Uffex
Thanks uffex and funwithfuel for your help. My problem was a broken connector before the power shift valve. Come to find out thanks to the service manual, I was looking at the wrong proportional solenoid. I’m not sure what the solenoid does at the very bottom of the pic. Anyone know? I still don’t have power to that but it doesn’t make a difference. I’m thinking that’s for a power boost function? The power shift solenoid is the one located on the top of the pump closest to the engine.
Does this happen with all functions, ie both sticks. Do both pumps stroke up to 4k ? Is your machine equipped with 2 pump flow? Do you have X1 or X3 (hammer/shear, slope and rotate) does it have the same issue when in travel? How does it behave with throttle in "F" mode, not g or h or i , F? Very important.
Good day The proportional valve at the lower part of the photo appears to be that used to control pump flow for option equipment, if you take a look at the right side of the seat in the cab you will find a plastic dome, remove this and you will find a slotted screw head to a rotary switch the same as used for the engine speed. This is used to control pump flow for a hammer for example. Kind regards Uffex