Onan RV fault codes

Onan (Cummins) generators power many motorhomes. Faults are shown as blink codes on the generator status light or as numeric fault codes on a display panel.

Generator

Start here Onan generator fault codes: reading the blinking status light An Onan RV genset reports every abnormal shutdown by blinking the status light in the control switch. Counting the blinks is easy; knowing which table to read them against is the part that goes wrong.

Fault 1
Engine over temperature — a first-level fault shown as o… Fault 2 (Low Oil)
Low oil pressure — a first-level fault shown as two blin… Fault 3
Service check — a first-level fault shown as three blink… Fault 4
Overcrank — a first-level fault shown as four blinks. Th… Fault 12
Overvoltage fault. The controller could not keep the out… Fault 13
Undervoltage fault. The controller could not hold the ge… Fault 14
Overfrequency fault. The engine governor could not hold … Fault 15
Underfrequency fault. The engine governor could not keep… Fault 19
Governor actuator fault. The controller detected an open… Fault 22
Governor actuator overload. The controller had to hold t… Fault 24
Faulty engine temperature sender. After ten minutes of n… Fault 27
Voltage sense fault. The controller was unable to sense … Fault 29
High battery voltage fault. The voltage across the gense… Fault 31
Overspeed fault. The engine speed exceeded 3400 rpm, so … Fault 32
Low cranking speed fault. During start the engine cranke… Fault 36
Engine Stopped fault. The engine stopped on its own with… Fault 38
Overcurrent (field overload) fault. The generator saw ex… Fault 57
Overprime. A control switch — the one on the genset or t…