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Cummins/Onan QSL9-G2 Engine

The Cummins/Onan QSL9-G2 is a 8.9 L 6-cylinder turbocharged and cac engine rated at 1500 rpm, producing up to 271.5 kW. It powers generator sets from Cummins/Onan and MQ Power, including the DSHAA 60 Hz, DSHAC and 1200 Amp Diesel Studio Generator. It holds 26.5 L (7.0 gal) of oil and 29.5 L (7.8 gal) of coolant.

Also known as: Cummins QSL9-G2

Part of the Cummins/Onan QSL9 engine family — 17 variants share parts & fitment.

8.9 L
Displacement
6
Cylinders
1500 rpm
Rated speed
271 kW
Gross power

Engine specifications

Oil capacity26.5 L
Coolant capacity29.5 L
Displacement8.9 L
Cylinders6
AspirationTurbocharged and CAC
Rated speed1500 rpm
Gross power271 kW

Common problems

15
  • Low battery voltage (Warning) — PCC voltage supply approaching level at which unpredictable operation may occur. 441
    Cause: Weak or discharged battery.
    Fix: Recharge or replace the battery. Specific gravity for a fully charged battery is approximately 1.260 at 80 F (27 C).
  • Low AC voltage (Shutdown) — Engine will shut down. 1447
    Cause: Fault simulation was enabled with InPower.
    Fix: With InPower, verify that the related fault simulation is not enabled. If you do not have InPower, remove battery power from the control to disable fault simulation overrides.
  • Fail to crank (Shutdown) — Engine will not start. 1438
    Cause: Starter is bad.
    Fix: Reset the control. Attempt to start, and test for B+ at the starter. If there is B+ at the starter, the starter could be bad. Test starter (see engine service manual). Replace the starter. If B+ is not present at the starter, go to next step.
  • Weak battery (Warning) — No action is taken by the PCC. 1442
    Cause: Weak or discharged battery.
    Fix: Recharge or replace the battery. Specific gravity for a fully charged battery is approximately 1.260 at 80 F (27 C).
  • Under frequency (Shutdown) — Generator set will shut down. 1448
    Cause: Fault simulation was enabled with InPower.
    Fix: With InPower, verify that the related fault simulation is not enabled. If you do not have InPower, remove battery power from the control to disable fault simulation overrides.
  • Engine does not crank in manual mode (no fault message) — Engine will not start
    Cause: No power supplied to control. (Control Alive indicator on Base board is not flashing.)
    Fix: Poor battery cable connections. Clean the battery cable terminals and tighten all connections.
  • Over frequency (Warning) — No action taken by the PCC. 1449
    Cause: Fault simulation was enabled with InPower.
    Fix: With InPower, verify that the related fault simulation is not enabled. If you do not have InPower, remove battery power from the control to disable fault simulation overrides.
  • KW overload (Warning) — No action taken by the PCC. 1444
    Cause: Fault threshold is not set correctly with InPower.
    Fix: Reset the threshold to the highest allowable setting. Determine the required operating range before adjusting the threshold.
  • High AC voltage (Shutdown) — Engine will shut down. 1446
    Cause: Fault simulation was enabled with InPower.
    Fix: With InPower, verify that the related fault simulation is not enabled. If you do not have InPower, remove battery power from the control to disable fault simulation overrides.
  • CAN DATALINK LOST MESSAGES (WARNING) — Engine will not start (If fault occurred during genset operation, genset may continue to operate). 427
    Cause: Power removed from ECM (keyswitch) during genset operation. O pressed on control during genset operation. (This is a nuisance fault only, not a critical fault.)
    Fix: Reset control by pressing Fault Reset button with O/Manual/Auto switch in O (Off) position.
  • J1939 time out error 285
  • High fuel supply pressure 442
  • High battery voltage (Warning) — PCC damage will occur. 442
    Cause: Excessive battery charging voltage.
    Fix: Adjust charge rate of AC powered battery charging circuit according to manufacturers instructions.
  • CAN engine shutdown (Shutdown) — Engine will not start. 1245
    Cause: No B+ at Keyswitch input to CM850 module.
    Fix: Refer to code 427 instructions.
  • Speed signal lost 115

Compiled from service & troubleshooting documentation across every generator set that uses the Cummins/Onan QSL9-G2.

Maintenance schedule

ItemSpecCapacityPart #Interval
Air filterReplaceable, Paper insert—100 hr
Fuel filterSpin-on type—100 hr
Oil filterFull flow, spin-on—100 hr
Battery2 x 750 cca—100 hr
BeltMechanical Fan Drive—100 hr
Coolant29.5 L—
Oil26.5 L—
Spark plugN/A—

Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.

Service intervals

2
ItemActionHoursMonthsNotes
valve clearanceCheck2000 hrB-Series (4BT3.3): valve clearance checks not required for 2000 hours, twice the industry standard
engine overhaulOther20000 hrQSK23-Series: expected life cycle to 20,000 hours before first overhaul

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Service specifications

60
TypeItemValueUnitCondition
OtherAlternator cooling air flow41.3m3/min
OtherAlternator excitation current - full load2.2amps
OtherAlternator excitation current - no load0.5amps
OtherCombustion air flow - standby20.9m3/minstandby rating
OtherCompression ratio16.8:1
OtherCooling system air flow248m3/minstandard set-mounted radiator
OtherCycle cranking - number of starting cycles1 to 7cycles
OtherExhaust flow at set rated load - standby33.3m3/minstandby rating
OtherFault current regulation (max output current on any phase under fault)3times rated currentsingle and three phase faults
OtherFrequency regulationIsochronous
OtherFull load acceptance - frequency dip / recovery time12.6% / 3.7% / secondsNFPA 110 single step load
OtherFull load acceptance - voltage dip / recovery time29.1% / 3.2% / secondsNFPA 110 single step load
OtherFull load rejection - frequency rise / recovery time3.9% / 2.9% / secondsload rejection
OtherFull load rejection - voltage rise / recovery time18.4% / 1.5% / secondsload rejection
OtherGovernor regulation classISO 8528 Part 1 Class G3
OtherGround fault warning (optional) sensing range100-1200amps, time delay 0-1 s600 VAC class, solid ground
OtherMaximum air cleaner restriction with clean filter3.7kPa
OtherMaximum surge power233kWPTS test
OtherMotor starting kVA at 90% sustained voltage - PMG excitation920kVAPTS test
OtherMotor starting kVA at 90% sustained voltage - shunt excitation770kVAPTS test
OtherOver current shutdown (51)>110 and <175% of rating
OtherOver current warning>110 for >60 s, or >400 for >1 s% of rating
OtherOver frequency shutdown/warning (81o)0-10Hz above nominal, 0-20 s time delaydefault disabled
OtherOver load (kW) warning default105% of rated kW, 60 s delayrange 50-140%, 0-120 s
OtherRandom frequency variation± 0.25%
OtherReverse Var shutdown default0.2per unit, 10 s delaythreshold 0.15-0.50, delay 10-60 s
OtherReverse power shutdown (32) default10% of standby kW rating, 3 s delayrange 5-20%, delay 1-15 s
OtherShort circuit shutdown>175% of rating
OtherTime delay start0-300secondsdefault 0 s
OtherTime delay stop (cool down)0-600secondsdefault 0 s
OtherTotal heat rejection - standby7.8MJ/minstandby rating
OtherUnder frequency shutdown (81u) default6Hz below nominal, 10 s time delayadjustable 0-10 Hz, 0-20 s
PressureBMEP at set rated load - prime1816kPaprime rating
PressureBMEP at set rated load - standby1979kPastandby rating
PressureMaximum back pressure10.2kPa (41.0 in H2O)
PressureMaximum exhaust back pressure10.2kPa
PressureMaximum fuel inlet restriction152.4mm Hg
PressureMaximum fuel return restriction254.0mm Hg
PressureMaximum inlet restriction152.4mm Hg (6.0 in Hg)
PressureMaximum return restriction254.0mm Hg (10.0 in Hg)
ResistanceAlternator rotor resistance2.0ohmsat 20 deg C
ResistanceAlternator stator resistance0.0128ohms per phaseat 20 deg C
SpeedAlternator maximum speed2250rpm
SpeedEngine overspeed limit2100 +/- 50rpm
SpeedIsochronous governing, steady state load no load to full load+/-0.25%
SpeedOver speed shutdown (default setting)115% of nominal
SpeedOverspeed limit2100 ± 50rpm
SpeedOverspeed shutdown default115% of nominal
SpeedRandom frequency variation (PTS test)+/-0.25%
SpeedRated speed1800rpm
TemperatureBattery charger ambient temperature operation at full rated output-20 to 45deg Cfull rated output
TemperatureControl operating ambient temperature range-40 to +70deg C
TemperatureCooling system ambient design - prime48deg Cstandard set-mounted radiator, non-seismic
TemperatureCooling system ambient design - standby52deg Cstandard set-mounted radiator, non-seismic
TemperatureExhaust temperature600°C (1110 °F)standby at set rated load
TemperatureExhaust temperature at set rated load - prime572deg Cprime rating
TemperatureExhaust temperature at set rated load - standby600deg Cstandby rating
TemperatureStandard temperature rise150°CStandby at 40 °C ambient
TorquePiston speed8.7m/s1800 rpm
VoltageAlternator voltage adjustment (operator)+/-5%

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Recommended fluids

FluidGradeStandardAmbientCapacityNotes
FuelNo. 2 diesel fuelDirect injection, number 2 diesel fuel
FuelNumber 2 diesel fuelDirect injection fuel system

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Fault codes

7
CodeNameMeaningSeverityAction
27Low AC voltage shutdownVoltage on any phase has dropped below a preset value; adjustable 50-95% of reference voltage, time delay 2-10 s.ShutdownDefault 85% for 10 seconds; function tracks reference voltage.
32Reverse power shutdownAdjustment range 5-20% of standby kW rating, delay 1-15 seconds.ShutdownDefaults 10%, 3 seconds.
51Over current shutdownOutput current on any phase more than 110%, less than 175% of rating and approaching thermal damage point of alternator.ShutdownControl includes algorithms to protect alternator from repeated over current conditions over a short period.
59High AC voltage shutdownOutput voltage on any phase exceeds preset values; time to trip inversely proportional to amount above threshold. Adjustable 105-125% of nominal, time delay 0.25-10 s.ShutdownDefault 110% for 10 seconds.
81oOver frequency shutdown/warningAdjustable 0-10 Hz above nominal frequency, time delay 0-20 seconds.Defaults: disabled.
81uUnder frequency shutdownGenerator set output frequency cannot be maintained; adjustable 0-10 Hz below nominal governor set point, 0-20 s delay.ShutdownDefault 6 Hz, 10 seconds.
-Reverse Var shutdownShutdown level adjustable: threshold 0.15-0.50 per unit, delay 10-60 seconds.ShutdownDefaults 0.20, 10 seconds.

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Procedures

1
Circuit breaker catalog number lookup operation

⚠ If the first 3 letters are PJP, start the search with PJ only.

⚠ If the catalog number starts with N, skip the N and begin the search with the second letter.

  1. Locate the circuit breaker feature code or part number.
  2. Use the charts to find the corresponding manufacturer circuit breaker catalog number.
  3. Use the first letter of the catalog number to determine the breaker frame (if first letter is N, use the second letter).
  4. Follow the corresponding website link to find the breaker catalog number description.
  5. Search the catalog using the first 3 letters and first 5 numbers of the breaker catalog number.

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Voltage reconnection

VoltagePhaseConnectionLeadsNotes
120/2083three phase reconnectable12
120/208 thru 139/240three phaseBroad range12150 deg C rise rating 230 kW / 288 kVA per ADS-212
120/2401single phase non-reconnectable4Double delta, 4 lead
120/240single phaseDouble delta4125 deg C rise rating 175/219 kW/kVA; 105 deg C rise rating 157/196 kW/kVA
120/2411single phase non-reconnectable
127/2201single phase non-reconnectable
139/2401single phase non-reconnectable
220/3803three phase reconnectable12
240/4163three phase reconnectable12
240/416 thru 277/480three phaseBroad range12150 deg C rise rating 255 kW / 319 kVA
254/4403three phase reconnectable12
277/4803three phase reconnectable12
347/6003three phase reconnectable12Lower broad range
347/600three phaseUpper broad range (LBR)6150 deg C rise rating 230 kW / 288 kVA; lower broad range 110/190 thru 120/208, 220/380 thru 240/416

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Parts cataloged across the Cummins/Onan QSL9 family

130
Part #DescriptionCategory
89285829Filter, airAir filter
89288971Element, air filter (main)Air filter
89288989Element, air filter (safety)Air filter
4021518Alternator ManualAlternator
431PSL6206Marathon Magna Plus / 431PSL6206Alternator
PI144D1Alternator ModelAlternator
UC274CAlternator ModelAlternator
UC274KAlternator ModelAlternator
22113039Belt, driveBelt
0518-0548-15ClampClamp
0518-0548-22ClampClamp
0518-0548-29ClampClamp
0518-0548-35ClampClamp
A056F113ClampClamp
22177745Conditioner, coolantCoolant filter
QSL9-G2Cummins / QSL9-G2Engine
22177711Filter, fuelFuel filter
36845022Filter, fuelFuel filter
35328251GASKETGasket
39487830GasketGasket
89202022Element, with gasketsGasket
89285761Element, with gasketsGasket
89287346GasketGasket
89288492GasketGasket
89304059GasketGasket
89304067GasketGasket
95214524GasketGasket
A052T655GasketGasket
A047A980Heater, BlanketHeater
22138259Hose assemblyHose
36890650Hose assemblyHose
54378526HoseHose
89299424Hose assemblyHose
92895267HoseHose
A045P359Hose, DEFHose
A045P417Hose, DEFHose
A051B439Hose, DEFHose
22177737ENGINE OIL FILTEROil filter
36860336ELEMENT, FILTER — compressor oil filter elementOil filter
1000ALCD AmmeterService part / kit
22354351HP, XP, MHP, VHP KIT–2000 HOURSService part / kit
22354369SHP, XHP KIT–2000 HOURSService part / kit
22354377KIT–1000 HOURSService part / kit
22354385KIT–500 HOURSService part / kit
22354393KIT–0–50 HOURSService part / kit
35092279Filter assemblyService part / kit
35370063ElementService part / kit
35592534DIAPHRAGMService part / kit
36756120Filter assemblyService part / kit
36844579'Y' strainerService part / kit
36844975BATTERY, 1000 CCAService part / kit
54731617Separator, waterService part / kit
54731625Filter, primaryService part / kit
54738992Filter, secondaryService part / kit
54739057ElementService part / kit
54739065ElementService part / kit
89285161Element, separatorService part / kit
91112201Separator, waterService part / kit
92451962FilterService part / kit
92452192FilterService part / kit
92951075Kit, minimum pressure valveService part / kit
A030X751BoxService part / kit
A030Y642HingeService part / kit
A031A954Panel, EnclosureService part / kit
A034N673Grill, EnclosureService part / kit
A034N943Bolt, CarriageService part / kit
A034P011Bolt, CarriageService part / kit
A034P012Washer, FlatService part / kit
A034P026Screw, Hex Flange HeadService part / kit
A034P039NutService part / kit
A034P108Screw, Hex Flange HeadService part / kit
A035H898Screw, Hex HeadService part / kit
A035P345Lead, ElectricalService part / kit
A041D550Header, DoorService part / kit
A041E195Panel, EnclosureService part / kit
A041E396Panel, EnclosureService part / kit
A041E596Header, DoorService part / kit
A041E928Post, EnclosureService part / kit
A041M317Door, ControlService part / kit
A041S526Insulation, DoorService part / kit
A046F214Panel, EnclosureService part / kit
A046F238Panel, EnclosureService part / kit
A047V570Panel, WindowService part / kit
A052S411LatchService part / kit
A053J589Screw, Hex HeadService part / kit
A053J591Screw, Hex HeadService part / kit
A053T433Padlock, AttachmentService part / kit
A055G556Screw, Socket HeadService part / kit
A056C784Latch, MechanicalService part / kit
A056H470HingeService part / kit
A056M306Bolt, CarriageService part / kit
A063L015Door, EnclosureService part / kit
A063L064Header, DoorService part / kit
A063L069Header, DoorService part / kit
A063L072Panel, EnclosureService part / kit
A063L080Panel, EnclosureService part / kit
A064U218Cover, Electrical ConnectorService part / kit
A072Y708Door, EnclosureService part / kit
A072Y709Panel, EnclosureService part / kit
V2403-M-E3BGEngine ModelService part / kit
A045J792Pump, Doser (See Page 70 for Components)Pump
0821-0016Screw, LockingScrew
0821-0029Screw, LockingScrew
0821-6002-03Screw, Hex HeadScrew
0821-6003-01Screw, Hex HeadScrew
22243141O–ring, IQ filter spacerSeal
22243158O–ring, IQ filterSeal
35279942O-RINGSeal
35328244SEALSeal
36865962Seal, greaseSeal
92293661Seal, sight glassSeal
92864115SealSeal
95765806'O' RingSeal
95823688'O' RingSeal
A030Y648Edging, SealSeal
A047V572Seal, WeatherSeal
A054S414Seal, DoorSeal
A054S416Seal, DoorSeal
22094759FUEL LEVEL SENDERSensor
22102339COOLANT LWL SWHSensor
22155451FUEL SENDERSensor
36841138COMP. & ENGINE TEMP SENDERSensor
36847838ENGINE/COMPR. AIR FILTER RESTRICTION SW.Sensor
36870608150 PSI PRESSURE SENDERSensor
36898922Sensor, temperatureSensor
369208250-100 PRESS TRANSSensor
544967730-225 PRESS TRANSSensor
A046D072Strap, TankStrap
A049G884Tank, DEF Complete (Includes Header and Heated Blanket) (See Page 66 for Components)Tank
36893824Valve, thermostaticThermostat

Parts cataloged across all variants of this engine family — verify the exact part fits your specific variant and serial number before ordering.

Common questions

What is the oil capacity of the Cummins/Onan QSL9-G2?

The Cummins/Onan QSL9-G2 engine has an oil capacity of 26.5 liters.

What is the displacement of the Cummins/Onan QSL9-G2?

The Cummins/Onan QSL9-G2 has a displacement of 8.9 liters with 6 cylinders.

Which generators use the Cummins/Onan QSL9-G2 engine?

The Cummins/Onan QSL9-G2 powers 7 generator set(s), including Cummins/Onan DSHAA 60 Hz, Cummins/Onan DSHAC, Cummins/Onan QSL9-G2, MQ Power 1200 Amp Diesel Studio Generator, MQ Power 1400 Amp Diesel Studio Generator.

What is a common problem with the Cummins/Onan QSL9-G2 engine?

A commonly reported issue on generators using the Cummins/Onan QSL9-G2 is: Low battery voltage (Warning) — PCC voltage supply approaching level at which unpredictable operation may occur.. Cause: Weak or discharged battery.. Fix: Recharge or replace the battery. Specific gravity for a fully charged battery is approximately 1.260 at 80 F (27 C)..