Onan generator · 2 model lines
Onan generator code 56
Onan documentation describes 56 separately for each model line: HGJAA / HGJAB / HGJAC (QG 5500/7000 EFI) operator manuals (“MAP Sender”); QG 2800i / 2500i LP (HGLAA Spec A-B) (“MAP Sensor Circuit Fault”). Compare the wording for your model below.
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 56 means by model
| Model line | What the manufacturer says | Source |
|---|---|---|
| HGJAA / HGJAB / HGJAC (QG 5500/7000 EFI) operator manuals | The Cummins Onan operator manual lists Code 56 as MAP Sender. | Cummins Onan RV Generator Manuals 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 2800i / 2500i LP (HGLAA Spec A-B) | The Cummins Onan QG 2800i/2500i LP HGLAA operator manuals list Code 56 as MAP Sensor Circuit Fault. | Cummins Onan RV Generator Manuals Cummins Onan QG 2800i/2500i LP HGLAA Spec A Operator Manual A062Y985 Cummins Onan QG 2800i/2500i LP HGLAA Spec B Operator Manual A075S349 |
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
- 37 Invalid Generator Set Configuration
- 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
- 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 2800i / 2500i LP inverter generators
Full table: Cummins Onan QG 2800i / 2500i LP inverter generators
- 1 High Engine Temperature
- 4 Over Crank
- 6 Low Oil Level
- 12 Output Over Voltage
- 13 Output Under Voltage
- 14 Output Over Frequency
- 15 Output Under Frequency
- 19 Actuator Circuit Fault
- 25 Alternator Over Voltage
- 26 Alternator Under Voltage
- 27 PMA Sense Lost
- 29 Battery Over Voltage
- 31 Engine Over Speed
- 32 Crank Under Speed
- 34 High Inverter Temperature
- 35 EE Checksum Fault
- 36 Mechanical Fault
- 38 Output Over Load
- 43 RAM Fault
- 45 Crank Position Sense Lost
- 49 Actuator Over Load
- 52 Injector/Lift Pump Circuit Fault
- 53 Oil Temperature Sensor Circuit Fault
- 54 MAT Sensor Circuit Fault
- 67 IGBT Over Current Fault
- 74 Unprogrammed Board
- 81 Alternator Stator Circuit Fault
- 82 Vent Pressure Sensor Circuit Fault