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Hitachi Ex120 Problem

Discussion in 'Excavators' started by spunkeymonkey, Jul 7, 2009.

  1. rgl726

    rgl726 Well-Known Member

    Joined:
    Sep 11, 2010
    Messages:
    175
    Location:
    cebu city, philippines
    Thanks 3doc,

    i trace all the wiring linking the all the pump solenoid and sensors and all has a continuity inside the cab with no ground.

    How will i test this sensors if they are good or bad?

    Angle sensor
    pressure sensor
    rpm sensor
    and the sensor in the control valve
     
  2. -3Doc

    -3Doc Well-Known Member

    Joined:
    Jul 29, 2009
    Messages:
    119
    Occupation:
    Ticketed HD Mechanic
    Location:
    British Columbia
    Send me a PM and I will get the info to you.
    Thanks.
     
  3. rgl726

    rgl726 Well-Known Member

    Joined:
    Sep 11, 2010
    Messages:
    175
    Location:
    cebu city, philippines
    hi -3doc,

    i would like to ask where is the homerun of the swing dampener sensor?

    i was able to trace one wire to the pvc but i cant find the other one in the pvc or ecu?

    i was able to trace it only up to the smj connector but from smj to the pvc or ecu i cant find it?

    is the other wire going somewhere else rather than the pvc or ecu?
     
  4. -3Doc

    -3Doc Well-Known Member

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    Jul 29, 2009
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    Occupation:
    Ticketed HD Mechanic
    Location:
    British Columbia
    Here is wiring schematic.
     

    Attached Files:

  5. PBR

    PBR New Member

    Joined:
    Sep 5, 2010
    Messages:
    4
    Location:
    Florida
    Dose any one know what Code 22 is on a EX120-2 and how to fix it Thanks
     
  6. Sripola

    Sripola Well-Known Member

    Joined:
    Nov 15, 2009
    Messages:
    57
    Location:
    USA
    Hi guys,

    Had a similar problem which i have posted in another thread, but if its any help we had a problem on a 97 Hitachi EX200-3. The machine was overheating after about 20mins of working. Both engine and hydraulic oild were getting very hot and the machine would stall.

    So one of the local techies swapped a DP sensor and everything was sorted!

    Hope this info helps
     
  7. Clay35441

    Clay35441 Member

    Joined:
    Nov 11, 2010
    Messages:
    7
    Location:
    Alabama
    Hi -3 Doc,

    New here but having same problems as everyone else. Cylinders on 120-2 max out and machine dies. I've traced entire wiring harness. Repaired wiring harness to solenoid valves but still doing the same thing. Are there any codes that the computer can give as to the problem? How do I get the computer to give me the codes?
    Please help.
     
  8. Clay35441

    Clay35441 Member

    Joined:
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    Location:
    Alabama
    I failed to mention that there is 25 volts going to both solenoid valves on the yellow wires but I'm not reading any voltage on the engine speed sensor that's next to the angle sensor.
     
  9. rgl726

    rgl726 Well-Known Member

    Joined:
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    Location:
    cebu city, philippines
    code 22 is problem with the angle sensor, high speed solenoid and, PVC.
     
  10. -3Doc

    -3Doc Well-Known Member

    Joined:
    Jul 29, 2009
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    119
    Occupation:
    Ticketed HD Mechanic
    Location:
    British Columbia
    Clay send me a PM and I will help you with some printed procedures.
    :)
     
  11. Clay35441

    Clay35441 Member

    Joined:
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    Location:
    Alabama
    Not sure how to send a pm. Here's my email address
    clay_smalley@msn.com
     
  12. Clay35441

    Clay35441 Member

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    Not sure how to send a pm
     
  13. dale

    dale New Member

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    Aug 23, 2010
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    Location:
    pa.
    ex120-2 throttle motor will not respond, have repalced motor, sensor, and rebuilt circut board. throttle motor only humes for a few seconds and then stops, will not move. I was also told if you unplug the motor and turn the key on this will cause the circut board to burn up. Is the true?? need help
     
  14. Clay35441

    Clay35441 Member

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    Location:
    Alabama
    -3doc
    Thanks to your help I've found that my problem is the Q5 resistor inside my pvc. Where can I buy replacement resistors?
     
  15. auy_tong2

    auy_tong2 Well-Known Member

    Joined:
    Dec 1, 2010
    Messages:
    49
    Location:
    Hongkong
    hi can somebody help me??? i need a ex120-2 repair manual, schematics, the hydraulics system is very slow, the hydraulics is like on the limp mode...
     
  16. rgl726

    rgl726 Well-Known Member

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    Location:
    cebu city, philippines
    maka ayo ta ana sir.
     
  17. auy_tong2

    auy_tong2 Well-Known Member

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    Location:
    Hongkong
    im looking for a manual sir :)
     
  18. auy_tong2

    auy_tong2 Well-Known Member

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    Location:
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  19. -3Doc

    -3Doc Well-Known Member

    Joined:
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    Occupation:
    Ticketed HD Mechanic
    Location:
    British Columbia
    Send me a PM and I can help you with manuals.:)
     
  20. Clay35441

    Clay35441 Member

    Joined:
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    Location:
    Alabama
    Can anyone tell me what the ohm and voltage ratings are on the Q5 transistor are inside the pvc. I'm having trouble finding the transistor because there aren't any markings on it. EX 120-2