Kholer power systems generators 18RESL auto shut down code UU

has it got fuel in it.

If it has a couple hundred hours or more, try cleaning the slips rings on the back of the rotor shaft. They should be very shiny and not black or polished looking.

The monitoring system of our Kohler propane generator has sent a "UU" message. What does this mean as it causes the generator to shut down 10 seconds after starting? Also how can this be corrected?

You have to reset it because it locked out on on under frequency. Just pullout the fuse on the control panel and then reinstall it a couple of seconds later. Now it will reset the fault codes. Hope that helps.

change the temp sensor and re test the gen set these have a bord that senses if theirs a issue with the engine and will cut the bower to the get head so theirs no load on some mod's then when the temp reaches a higher point they shut down. re-post is this does not fix the issue i will review the books on the unit.
hope this helps

Here is the code explained direct from Kohler's manual. I'd disconnect the generator load first.
UU Undervoltage Shutdown occurs if the voltage falls below 80% of the nominal system voltage for more than seconds. Check wiring and connections.
Reduce the load and restart the generator set. —
Check wiring and Check controller configuration, system voltage
and frequency (parameter UU).

Check AC voltage and adjust, if necessary. 5.7
Replace the SCR module and test voltage again. 4.9
Separately excite unit. 5.2
Check stator continuity

See web site for manual :http://www.kohlerpower.com/onlinecatalog/pdf/tp6196.pdf

Means that the engine has turned over for too long without starting. It times out to protect the starter and battery wiring.

U need to make sure that the relay driving ur auto start stay closed all thru the crank cycle.

call koler but ui think is meant high heat as in the thermal circut is shuting you down or low oil
could be a couple of things best bet call kohler

Could be the battery voltage. If your battery is not charging properly, the controller on the unit can do some funky things! Exactly how long does it run for? Is this in auto or manual mode?