Onan generator · 6 model lines

Onan generator code 42: Processor

Onan documentation for 6 model lines lists 42 as “Processor”.

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 42 means by model

Model lineWhat the manufacturer saysSource
HGJAA / HGJAB / HGJAC and HGJBB operator manualsThe Cummins Onan operator manual lists Code 42 as Processor.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 42 as Processor.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 42 as Processor.Cummins Onan RV Generator Manuals
Cummins Onan QG 4000/3600 LP KYD Spec A-C Operator Manual 981-0169
Quiet Diesel 5000 (HDKBA)The Cummins Onan Quiet Diesel 5000 HDKBA operator manual lists Code 42 as Processor.Cummins Onan RV Generator Manuals
Cummins Onan Quiet Diesel 5000 HDKBA Operator Manual 0981-0166
Quiet Diesel 6000 / 7500 / 8000 (HDKAH, HDKAJ, HDKAK)The Cummins Onan Quiet Diesel 6000/7500/8000 HDKAH/HDKAJ/HDKAK operator manual lists Code 42 as Processor.Cummins Onan RV Generator Manuals
Cummins Onan Quiet Diesel 6000/7500/8000 HDKAH/HDKAJ/HDKAK Operator Manual A046L053
Quiet Diesel 10000 / 12500 (HDKCA, HDKCB)The Cummins Onan Quiet Diesel 10000/12500 HDKCA/HDKCB operator manual lists Code 42 as Processor.Cummins Onan RV Generator Manuals
Cummins Onan Quiet Diesel 10000/12500 HDKCA/HDKCB Operator Manual A043D713

What you can safely check

  • Turn the generator off.
  • Record the code and do not attempt internal controller work.
  • Stop the generator.
  • Record the fault code, model/spec, hour meter, load, fuel state, and weather for Cummins service.
  • Record the blink code and call Cummins service.
  • Record the fault code, model/spec, hour meter, and loads running for Cummins service.

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.
  • Electrical output, inverter, controller, stator, rotor, fuel injection, sensors, wiring, coolant-system service, fuel leaks, and generator compartment repairs belong 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

Full code tables for these models

Related troubleshooting guides

Official sources