Kohler generator code Over Crank

High severity — The controller made three unsuccessful attempts to start the engine and locked out with an Over Crank shutdown fault.

Applies to: Kohler residential standby generators with an RDC2 or DC2 controller

What it means

Three tries and it gives up — that's the entire logic behind this fault. The RDC2 or DC2 controller cranks the engine, waits for a run signal, and if none arrives it tries twice more before locking the unit out completely rather than grinding the starter indefinitely. Unlike a warning that lets the generator keep running, Over Crank is a full shutdown: the display shows the fault, the unit won't attempt another start on its own, and it stays that way until someone clears it at the panel. The fault itself doesn't explain why the engine didn't catch — it only reports that three attempts failed — so real diagnosis starts with the two things most likely to keep any engine from firing at all: fuel and battery.

Most common causes

Kohler and most field technicians narrow this down to the same handful of culprits:

Fuel supply issue (closed LP/NG valve, empty tank, or stale gasoline on portable/older models)
Weak starting battery
Fouled spark plug(s) or ignition fault
Clogged fuel filter or carburetor issue

What you can check yourself

Work through these before touching anything else:

Verify the fuel valve is open and there's adequate LP/NG supply or fresh fuel
Check battery voltage and terminal connections
Press the controller's AUTO button to clear the fault after correcting fuel/battery, then attempt a start

Pay attention to how the engine cranks while you're troubleshooting: a strong, fast crank that just won't catch points toward fuel or spark, while a slow, labored crank points straight back at the battery.

Call a professional when: If fuel and battery are both confirmed good and the unit still won't start, or you notice a fuel smell while cranking, call a technician qualified to work on gas fuel systems rather than continuing to force restarts.

All codes for this brand

Every Kohler generator fault code — full list with what differs between models.

Related codes: Battery Voltage Low, Engine Oil Pressure Low, and M-N Invalid Shutdown Fault. See the Generator Won't Start symptom page for the wider troubleshooting flow.

Sources

Kohler 14/20RESA & RESAL RDC2/DC2 Operation Manual, Controller Fault Messages

This site is an independent reference and is not affiliated with, endorsed by, or sponsored by any generator manufacturer. It is not a substitute for a licensed electrician or generator technician. Standby and portable generators involve mains-voltage output and, on LP/NG units, a live fuel-gas supply — work on wiring, the transfer switch, or the fuel system should be done or verified by someone qualified to do it. Pages are written with AI assistance from the sources listed on each page and checked against them before publishing.