I got a ex120-5 a year ago with 11k hours. It ran strong till I parked it for few months. Now everything is slow tracks arm movements. The engine rpm works great. The turtle button never worked it was always one speed. I tried to read the ecu codes manually by connecting 2 top ports from a 4 port diagnostic connector by the fuse box. It blinks 8 times then pause then 9 then 8 then 9 on repeat. What does that mean?
Welcome to HEF. I suggest you try as following image attached.
What does perform retrial B mean. Is this the sensor. They are talking about? Because I can’t find angle sensor for 120-5
To do RETRIAL B you must have a tool called Dr.EX or Dr.ZX. See the attached file for more details. To buy A sensor (angle sensor), let go to Ebay. US Angle Sensor 4444902 for Hitachi Excavator EX120-2 EX120-3 EX200-2 EX200-3 | eBay Find many great new & used options and get the best deals for US Angle Sensor 4444902 for Hitachi Excavator EX120-2 EX120-3 EX200-2 EX200-3 at the best online prices at eBay! Free shipping for many products! www.ebay.com
My 120-5 does not have that. I looked everywhere
According to the photos you provided, your device is for the Japanese domestic market. I see you registered with the forum as you are in Washington. I didn't know there were Hitachi excavator for the Japanese domestic market in Washington!
Thanks for all of the info. I have the parts ordered. I’ll let you know how it goes
No difference
I swapped the sensors and no difference. Also checked the connectors with a volt meter and no power coming to them
I'd bet that is your problem. Start tracing the wires back and looked for chewed one.
T in gauges to the hoses that go to the back of the regulators . Should see pressure increase when moving the controls. If no pressure increases check the solenoids for gumming up inside . Can always bypass the solenoids