Hitachi EX135UR-5 won't throttle up

[Ronsii]

Had a machine the we had the boom line bored once... when we got it back all seemed well until I tried to use it at night... then we noticed none of the lights worked and it kept blowing fuses, took a while tracing wires to determine the guy doing the line bore had lit a fire under the cab and burned some of the main harness that carries the light circuit and many others. So just thought I'd share our experience in case you have a similar issue going on.

 

[johntims]

Spica const. I got it figured today and judging by what you have said I’m pretty confident we are having the same problem. Mine was a bad arm roll in pressure sensor. It is located in the pilot manifold just behind and below the cab. Being that yours is a zero tail swing it may be in a slightly different location. There should be two sensors in the manifold. The one with 3 wires going to it will be the arm roll in. The other will only have two wires. Unplug that sensor, if it’s your problem the machine should function as normal other than a code for that sensor having an open. It is possible that it could be one of the other 5v sensors on the machine causing it. If the arm roll in doesn’t take care of it you may want to try some of the others. There aren’t many so it’s pretty easy to narrow down once you have it figured out. Just unplug them one at a time until your throttle comes back.

 

[Martin Canuel]

I'm going through the same on my zx 225uslc Machine won't respond to throttle dial. Machine won't turn off with key. I've replaced the throttle motor and didn't fix it. On the 3 pins ec sensor while running at idle I read 4.5v 1.7v and ground. Regardless of throttle position those readings don't change. I read your write up and also tested the 4 pins on the motor side and pin 1 is (. 2 to 1.4) fluctuating pin 2 is (. 2v) pin 3 is (. 5v) and 4tj is ground. Any insight would be amazing I'm pulling my hair out. I've done a relearn probably 8 times doesn't do a thing. Motor doesn't even make sound now when starting. Randomly will work fine one day then next no response.

 

[Spiva Const]

I haven’t got mine figured out, I’m retired and have more than one so I just gave up for now.
Alibaba has hydraulic retrofit kits for some Hitachi models but not the EX 135. It uses pilot control hydraulic pressure to actuate a motor that pulls on the the throttle cable. If there are kits available it must be a common problem.

 

[JULIBERTH M. PAPASIN]

hi.. hitachi EX135UR-5, error code display E18 & E50, what is it mean?
please help me. Thank you

 

[joeblow]

It’s grey market and will drive you nuts.We spent hours on just that problem and went to a cable.Job done.