Komatsu PC 150 LC-6K Wont Swing

[bucwheat]

I am having a swing issue on a PC 150 LC 6K... Display shows E03 error code, which is swing brake system. This error was coming up intermittent... as soon as you moved joystick to swing, error would stop and machine would swing. Now its on all the time and machine will not swing at all. I was thinking perhaps a wiring issue or bad solenoid. I don't have a service manual and cannot seem to find the solenoid to test to see if that's the issue or not. Anyone have any ideas or insight as to what might be causing this?

 

[bucwheat]

Another symptom is if you turn the swing brake bypass switch on in the fuse compartment. It will cause the 10amp Governor fuse to blow. I am puzzled as to what the problem is.

 

[bucwheat]

Update.... Service code message 203 which i believe is a short circuit in swing holding brake solenoid. I only have the service code list for the Dash 7 series, but would assume its the same. Bad solenoid or bad wiring somewhere?

 

[John C.]

There is a solenoid stack behind the cab with four units. One of those will be the swing brake solenoid. You can follow the hydraulic hose back from the swing motor to the area where the solenoids are. There is a nut on the end of the solenoid you can remove and pull the coil off the valve stud. Test it with an ohm meter and likely it will be shorted inside the coil. If not you most likely have a break in your wiring harness touching bare metal on the machine somewhere.

 

[bucwheat]

Thanks John!!! I appreciate the info... I'll go check that now!