Onan generator · 3 model lines

Onan generator code 37

Most Onan documentation lists 37 as “Invalid Generator Set Configuration”. Some model lines word it differently or give it a different meaning: QG 4000 / 3600 LP KYD (Spec A-C) (“Invalid Genset Configuration”).

Check your model first. The same code can mean different things on different models. Find the model number on the appliance's data label, then use the matching row below.

What code 37 means by model

Model line	What the manufacturer says	Source
HGJAA / HGJAB / HGJAC and HGJBB operator manuals	The Cummins Onan operator manual lists Code 37 as Invalid Generator Set Configuration.	Cummins Onan RV Generator Manuals Cummins Onan Generator Set for RV Operator Manual A031C171 Cummins Onan Generator Set for RV Operator Manual A035D009 Cummins Onan RV Generator Set HGJAA/HGJAB/HGJAC Spec A-E Operator Manual 983-0101
QG 4000 / 3600 LP KY (Spec J-R)	The Cummins Onan QG 4000/3600 LP KY operator manuals list Code 37 as Invalid Generator Set Configuration.	Cummins Onan RV Generator Manuals Cummins Onan QG 4000/3600 LP KY Spec J-N Operator Manual 981-0159 Cummins Onan QG 4000/3600 LP KY Spec P-R Operator Manual A041D131
QG 4000 / 3600 LP KYD (Spec A-C)	The Cummins Onan QG 4000/3600 LP KYD operator manual lists Code 37 as Invalid Genset Configuration.	Cummins Onan RV Generator Manuals Cummins Onan QG 4000/3600 LP KYD Spec A-C Operator Manual 981-0169

What you can safely check

Turn the generator off.
Record the fault code, model/spec, hour meter, load, fuel state, and weather for Cummins service.
Stop the generator.

Stop and call a technician for

Internal generator electrical output, inverter, controller, sensors, fuel system, ignition, AC circuit, and engine diagnosis belongs to Cummins service or a qualified generator technician.

Generators can produce carbon monoxide, hot surfaces, fuel hazards, moving-part hazards, and lethal voltage. Shut the generator down and do not open energized compartments unless qualified.

Write this down before you call

generator model/spec letter
hour meter
fault blink count
loads running when the shutdown occurred

Other codes on Cummins Onan QG gasoline generators (HGJAA, HGJAB, HGJBB)

Full table: Cummins Onan QG gasoline generators (HGJAA, HGJAB, HGJBB)

2 Low Oil Pressure
3 Service Check
4 Over Crank
12 Over Voltage
13 Under Voltage
14 Over Frequency
15 Under Frequency
19 Governor Actuator
22 Governor Actuator Overload
23 Low Oil Pressure Cutoff Switch
27 Voltage Sense
29 High Battery Voltage
31 Over Speed
32 Low Cranking Speed
35 Control Card Failure
36 Engine Stopped
38 Over Current (Field Overload)
41 Generator Rotor
42 Processor
43 Processor
45 Speed Sense
47 Ignition
48 Generator Field Sense
51 Processor
52 Fuel Injector
54 MAT Sender
56 MAP Sender
57 Over Prime
58 Exhaust Gas Temperature Shutdown
81 Exhaust Gas Temperature Sensor Open
82 Exhaust Gas Temperature Sensor Shorted

Other codes on Cummins Onan QG 4000 / 3600 LP generators

Full table: Cummins Onan QG 4000 / 3600 LP generators

3 Service Check
4 Over Crank / Overcrank
12 Over Voltage / Overvoltage
13 Under Voltage / Undervoltage
14 Over Frequency / Overfrequency
15 Under Frequency / Underfrequency
27 Voltage Sense
29 High Battery Voltage
32 Low Cranking Speed
35 Control Card Failure
36 Engine Stopped
38 Over Current (Field Overload) / Overcurrent
41 Generator Rotor
42 Processor
43 Processor
45 Speed Sense
47 Ignition
48 Generator Field Sense

Related troubleshooting guides

Onan generator stopped and shows a fault code

Official sources

OnanCummins Onan RV Generator Manuals OnanCummins Onan Generator Set for RV Operator Manual A031C171 OnanCummins Onan Generator Set for RV Operator Manual A035D009 OnanCummins Onan RV Generator Set HGJAA/HGJAB/HGJAC Spec A-E Operator Manual 983-0101 OnanCummins Onan QG 4000/3600 LP KY Spec J-N Operator Manual 981-0159 OnanCummins Onan QG 4000/3600 LP KY Spec P-R Operator Manual A041D131 OnanCummins Onan QG 4000/3600 LP KYD Spec A-C Operator Manual 981-0169