Kohler 5ECD Fault Code UU

[firecadet613]

43 hours on my 5ECD. Ran just fine last time we used it, about three weeks ago. Went to fire up today, and first was a LOC. Checked the strainer and found a piece of plastic, removed and restarted. Code is UU. Tried multiple times, still code UU.

Any ideas where to look?

 

[JimG]

UU is undervoltage shutdown... manual says to reduce the load and try again.

 

[firecadet613]

No load on the genny...panel is still set to shorepower.

 

[Kendall]

Try a fresh battery to the generator....or a booster pack just to see. I thought UU was low voltage to the gen and makes her switch off.

 

[mainstream]

Try a fresh battery to the generator....or a booster pack just to see. I thought UU was low voltage to the gen and makes her switch off.[/QUOTE

Kendall
The error uu is loW voltage out put of generator, strator may be bad or bad control. If you have no load on gennie I would think it's a bad strator on the back end or the controller. It might be time for a kohler tech. Does the gennie run at the designated rpm that will cause issues also low rpm= low voltage

 

[KP49]

UU code could come from low rpm at start, you only have a few seconds for everything to check out before the control board shuts it down. Same will happen with the LOC if there isnt enough enough raw water pressure to trip the sender within a certain amount of time.

When it starts if it sputters or misfires for a few seconds it can trip either code, it should be at operating RPM within seconds after startup. If not a plug change or fuel system bleed may be needed. If it starts at running RPM almost instantly it could be a back end issue or controller as stated above.

 

[my DOG HOUSE]

I had the same thing on a few consecutive starts then I loaded it AC and water heater and it started ok. Had a hard time believing it would help, but others suggested I change the spark plugs. I did and it solved the problem, the rear one was bridged.

 

[Lanier Tom]

Have you tried resetting the generator? In the past I have gotten the UU code when I stopped the generator with the load still on it. To clear the error I killed the battery switches for a minute. When I turned everything back on the error was gone.
Not sure if this is your problem, but start with the easy.

 

[firecadet613]

Easy fix. Fuel pump relay was disconnected, not sure how that happened.