I have a Kohler 12RESM1 propane generator with oc/uu code

It sounds like you may have a problem with the fuel system on your Kohler 12RESM1 generator. When you start the generator and it runs for a few seconds before stopping, it could be an issue with the fuel supply or fuel delivery to the engine.

There are a few things you can check to troubleshoot the problem:

Check the fuel level in the tank. Make sure there is enough fuel to run the generator.

Check the fuel filter. If it is clogged, it could be restricting the flow of fuel to the engine.

Check the fuel pump. It could be malfunctioning or not delivering enough fuel to the engine.

Check the fuel lines. Make sure they are not clogged or leaking.

If you are unable to find the cause of the problem, it is recommended that you contact a certified service technician or the manufacturer for further assistance.

OC is Over Crank which generally means it cranked and cranked and failed to start. Turning the switch off and on again is the way to clear the fault. How long is it taking to start whilst cranking? It should start within 8 seconds

Check gas pressure. Oc is over crank. Means tried to start but did not.

UU is generator under voltage. Check to see if it does it without laod also. if it does you will need a pro to check and ohm the rotor and stator for shorts

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?

OC means OVERCRANK safety circuit stopped the auto start-up so you wouldn't burn up the starter. There is a reason the generator didn't start. Low battery, not enough fuel pressure, clogged air filter, bad starter... You just have to eliminate as many as you can visually. Rebooting the generator should clear the OC condition and you can try to start it manually.

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

Check battery volatge while you are cranking engine if voltage drops below 9 vdc you have a bad battery. If it doesn't you probable have a bad starting solenoid or a bad ground at the starting solenoid.

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?