Kohler Generator 5E LOC Error

[99problems]

Hello all,
I'm hoping someone can help. We have a 2006/07 Kohler 5E generator that will start but shuts down after 15 seconds with error code LOC. We have excellent water flow so that's not the problem. Here's what we've tried:

Removed and replaced impeller. No damage.

Removed and replaced the thermostat.

Filled and burped the coolant system. Temp after shut down was only 160F.

Removed and thoroughly cleaned the heat exchanger. Very little scale and no rubber. Replaced o-rings.

Removed and replaced pressure sensor.

Removed and replaced raw water line. It was corroded.

Replaced zinc anode.

Flushed raw water line.

What else can we look at before we give up?
Thanks.

[a64pilot]

What does the error code LOC refer to?
Whatever it is, I’d suspect the sensor that LOC is.

[99problems]

Loss of coolant

[a64pilot]

Ok, so a coolant level sensor then. That would be the fresh water side. You will likely have two sensors, a temp sensor and apparently a level sensor. My guess would be both in the heat exchanger tank.
Not to be insulting but be sure to take the cap off of the heat exchanger tank and be certain it’s full.
At least that’s my belief. Often you can bypass these sensors by shorting the wires together, but not always, so you need to find a manual.
Have you tried Googling one?
Now what I said I’m not certain about, but it’s my best guess. The manual should hopefully have a trouble shooting tree

[GordMay]

Greetings and welcome aboard the CF, 99.

[a64pilot]

This thread indicates that it’s actually a pressure switch on the heat ex, so it is raw water, it indicates that can simply disconnect the pressure switch.
Post number 8, googling Kohler 5E LOC error brings up a few others.

Kohler LOC error | Club Sea Ray

There are also maintenance manuals available, but I am real low band width so I didn’t download, but google will link to a couple.

[a64pilot]

Gord however is usually outstanding in finding manuals for people

[Crusty Joker]

I suggest that you bypass sensors by using jumper. Need to determine if it is normally open or normally closed switch, or a variable to ground as in the case of temperature probes.
Test accordingly. Will it run if you bypass the sensor / switch? You can make your own logic test for this. That I worked for Kohler many years ago only indicates my general respect for the company and engineers and sales people, but like Jaguar, and all other systems they are kind of lacking in the Navy Way... designed by genius to be operated by idiot... under any condition is not on the page 100%. Sometimes the design was in error, not the repairman and guy on the ground that needs to fix it. A team response works best. Hats off to the forum and its leaders! Kohler manuals are usually generic from my ancient experience. Keep computers away from marine engines. Analog worked. Keep it Simple.