• Thank you for visiting HeavyEquipmentForums.com! Our objective is to provide industry professionals a place to gather to exchange questions, answers and ideas. We welcome you to register using the "Register" icon at the top of the page. We'd appreciate any help you can offer in spreading the word of our new site. The more members that join, the bigger resource for all to enjoy. Thank you!

2008 Komatsu D31px21 Dozer with 2400 hours

Tim.stuart

New Member
Joined
Sep 20, 2017
Messages
3
Location
Texas
All, I am hoping someone here may have a little Komatsu Experience. I am currently digging a 2 acres pond on my place using my dozer. I was backing up at a rather slow speed and went to shift it from reverse to forward and when the shifter was about in the he neutral position I lost all power to the hydro tranny. Meaning when I move the shifter in forward or reverse I have nothing. I cant get it to move. It threw alarm codes DK31KB (steering angle sensor 2 : short circuit HST) , DK56KB (directional potentiometer 1 : short circuit HST) , DK57KB (directional potentiometer 2 : short circuit HST) , DK40KA ( Brake angle sensor disconnect HST), DK12KA (deceleration sensor disconnect HST), DAJ5KK (HST controller sensor Power-supply output disconnected HST), DK30KB ( steering angle sensor 1 short circuit HST), DK10kb (throttle angle sensor short circuit HST). All the info in the above () are from my book looking up the error codes. It seems to me all the errors are centered around the HST controller. So I have checked all the fuses and don't see any blown thinking I lost power to the HST controller but did not find a bad one.

Does anyone have any thoughts or recommendations on what to check next? Any way to do a total reset on the system?

The dozer up until now has been running great ! I bought about 6 months ago from a rental place and have put around 150 hours on it since the purchase so it's relative a new dozer to me. I am also new to the Komatsu world as I had a little Mitsubishi bd2h until I brought this one. The one thing I learned real quick when a Hydro hose started leaking is the Komatsu dealer is quiet proud of parts they wanted $650 plus shipping for the hose. So I cant afford just to start throwing parts at it.

Any help is greatly appreciated!!

Regards,

Tim
 

r20d12

Well-Known Member
Joined
Nov 29, 2009
Messages
123
Location
oklahoma
Occupation
heavy equipment field tech since July 1990
When alot of codes show up at once it is because those circuits have something in common like a shared ground or 5 volt supply that has broke or shorted (usually broke).
I've been a heavy equipment tech since July 1990.
 

r20d12

Well-Known Member
Joined
Nov 29, 2009
Messages
123
Location
oklahoma
Occupation
heavy equipment field tech since July 1990
Its hard to find without a schematic and a volt meter
 
Top