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Cummins/Onan 6CTAA8.3-G1 Engine

The Cummins/Onan 6CTAA8.3-G1 is a 8.3 L 6-cylinder turbocharged engine rated at 1500 rpm. It powers generator sets from Cummins/Onan, including the C200 D6, C220 D5 and DGFC. It holds 150 L (39.6 gal) of coolant.

Also known as: Cummins 6CTAA8.3-G1

Part of the Cummins/Onan 6CTAA8.3 engine family — 4 variants share parts & fitment.

8.3 L

Displacement

Cylinders

1500 rpm

Rated speed

On this pageSpecs Generator sets Maintenance FAQ Service intervals Torque & specs Fluids Fault codes Procedures Wiring

Engine specifications

Coolant capacity	150.0 L
Displacement	8.3 L
Cylinders	6
Aspiration	Turbocharged
Rated speed	1500 rpm

Generator sets powered by this engine

Cummins/Onan C200 D6 Cummins/Onan C220 D5 Cummins/Onan DGFC

How to read your Cummins/Onan engine serial & model number →

Common problems

Engine cranks but will not start
Cause: Empty fuel tank, fuel leaks, or plugged fuel lines
Fix: Correct as required
Over Current 1471
Low Coolant Level 197
Cause: Engine coolant level has fallen below the warning trip point
Fix: If generator is powering critical loads and cannot be shut down, wait until next shutdown period, then follow code 235 procedure; if engine can be stopped, follow code 235 procedure.
Weak Battery — Indicates that during cranking, the battery voltage is at or below the weak battery warning trip point for a time greater than or equal to the weak battery set time. 1442
Cause: During cranking, the battery voltage is at or below the weak battery warning trip point for a time greater than or equal to the weak battery set time
Fix: See code 441 for corrective action
Weak Battery 1442
Cause: During cranking, the battery voltage is at or below the weak battery warning trip point for a time greater than or equal to the weak battery set time
Fix: See code 441 for corrective action.
Under Frequency 1448
Too Long In Idle — Indicates genset has been in Idle mode too long (10 minutes maximum). 2342
Cause: Genset has been in Idle mode too long (10 minutes maximum)
Too Long In Idle (10 min.) 2342
Speed/Hz Match 1469
Speed Signal Lost — Battle Short is suspended and a shutdown occurs immediately. 121
Speed Signal Lost 121
Shutdown After BS 1123
Shutdown After Battle Short 1123
Cause: Moving the customer installed Battle Short switch to OFF with an active but overridden shutdown fault or a shutdown fault that was overridden at any time.
Short Circuit 1445
S1 CB Not Open 2397

Compiled from service & troubleshooting documentation across every generator set that uses the Cummins/Onan 6CTAA8.3-G1.

Maintenance schedule

Item	Spec	Capacity	Part #
Air filter	Normal duty air filter.		A054E584	Amazon eBay
Fuel filter	Oil and fuel filter fitted, water separator.		—
Oil filter	Oil and fuel filter fitted, water separator.		—
Battery	Set mounted starting battery.		—
Belt	Belt drive for alternator and starter.		—
Coolant	Cooling system: IC 01, radiator and Guarding in color: Black.	26.3	—
Oil	Lubrication system oil capacity	23.8 liters	—
Spark plug			—

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

Service intervals

Item	Action	Hours	Months	Notes
Charge air piping	Check	50 hr		Daily or after 8 hours
Coolant level	Check	8 hr		Daily or after 8 hours
Engine oil level	Check	8 hr		Daily or after 8 hours
Fuel Filter(s)	Drain	8 hr		Drain 1 cup or more of fuel to remove water and sediment. Refer to engine operation and maintenance manual for procedure.
Fuel Tanks (water and sediment)	Drain	8 hr		Drain 1 cup or more of fuel to remove water and sediment.
Fuel level	Check	8 hr		Daily or after 8 hours
General genset inspection	Inspect	8 hr		Daily or after 8 hours. Check for oil, fuel, cooling and exhaust system leaks; check exhaust audibly and visually with set running.
Inspect Genset	Check	8 hr		Check for oil, fuel, cooling and exhaust system leaks. Check exhaust system audibly and visually with set running and repair any leaks immediately.
Oil Level	Check	8 hr		Keep oil level near the dipstick high mark without overfilling.
Air Cleaner	Clean	50 hr		Clean if required. Perform more often in dusty conditions.
Air cleaner (clean if required)	Clean	50 hr		Weekly or after 50 hours; perform more often in dusty conditions
Battery charging system	Check	50 hr		Weekly or after 50 hours
Coolant heater	Check	50 hr		Weekly or after 50 hours
Crankcase Oil	Drain	50 hr		First service — Break-in: drain and replace the crankcase oil after the first 50 hours of operation on new generator sets.
Exhaust condensate trap	Drain	50 hr		Weekly or after 50 hours
Water and sediment from fuel tank	Drain	50 hr		Weekly or after 50 hours; drain 1 cup or more of fuel to remove water and sediment
Radiator hoses for wear and cracks	Inspect	100 hr		Monthly or after 100 hours
Starting batteries	Check	100 hr		Monthly or after 100 hours
Battery electrolyte level	Check	200 hr		Check at least every 200 hours of operation
Anti-freeze and DCA Concentration	Check	250 hr	3 mo	Refer to engine operation and maintenance manual.
Crankcase oil and filter	Change	250 hr	12 mo	Refer to Cummins Engine Operation and Maintenance Manual. Standby applications: change every 12 months or 250 hours, whichever comes first.
Drive Belt Tension	Check	250 hr	3 mo	Visually check belt for evidence of wear or slippage. Replace if hard or brittle. Refer to engine operation and maintenance manual.
Fuel Filters	Change	250 hr	3 mo	Refer to engine operation and maintenance manual.
Governor Adjustment	Check	250 hr	3 mo
Radiator Hoses for Wear & Cracks	Check	250 hr	3 mo
Air Cleaner Element	Change	500 hr		Perform more often in dusty conditions. Replace yearly or sooner if service indicator button pops up.
Coolant Filter	Change	500 hr	6 mo	Refer to engine operation and maintenance manual.
Cooling System	Clean	500 hr	6 mo	Refer to engine operation and maintenance manual.
Crankcase Breather	Clean	500 hr	6 mo	Refer to engine operation and maintenance manual.
Valve Lash	Adjust	1000 hr		After 1000 hours; contact an authorized service center for service
Alternator Bearings	Inspect	4000 hr	24 mo	Inspect all sealed bearings every 4000 to 4500 hours (10000 hr/2 years)
Alternator Bearings	Replace	30000 hr	60 mo	Replace all sealed bearings every 30000 hr/5 years (or if necessary after 10000 hr/2 years)
Air cleaner element	Replace		12 mo	Replace yearly or sooner if service indicator pops up; more often in dusty conditions
Generator set exercise	Test		1 mo	Exercise at least once a month for a minimum of 30 minutes at not less than 30 percent of nameplate rating

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

Type	Item	Value	Unit	Condition
Clearance	Float switch lift below C-clip stop	1/8	inch (3 mm)
Clearance	Overspeed switch magnet-to-fly arm air gap (minimum)	0.005	inches (0.13 mm)
Other	AC waveform Total Harmonic Distortion (THDV)	< 5% no load to full linear load, < 3% for any single harmonic	%
Other	BMEP at set rated load	2276 (330) / 2063 (299)	kPa (psi)	standby / prime
Other	Battery electrolyte corrected specific gravity (fully charged)	1.260		electrolyte temperature corrected
Other	Battery electrolyte specific gravity, fully charged (corrected)	1.260		corrected to 80 °F (27 °C)
Other	Battery recharge threshold specific gravity	1.215
Other	Battery specific gravity temperature correction	four gravity points (0.004) for every ten degrees above 80 F (27 C)
Other	Battery specific gravity, fully charged	approximately 1.260	at 80°F (27°C)
Other	Combustion Air	15.86 (560) / 15.38 (543)	m3/min (scfm)	standby / prime
Other	Cycle crank crank and rest time	7 to 20	seconds
Other	Cycle crank number of cycles	3, 4, or 5
Other	ECM fuse F1 (starter solenoid circuit)	20	amps
Other	ECM fuse F2 (fuel solenoid circuit)	20	amps
Other	ECM fuse F3 (continuous B+ to remote circuits)	15	amps
Other	ECM fuse F4 (ECM circuits)	5	amps
Other	ECM fuse F5 (engine gauge circuits)	5	amps
Other	Frequency adjustment range	±5%	%	genset running
Other	Frequency regulation	Isochronous
Other	Fuse A31-F1 (control B+)	5	Amp	Engine Interface board
Other	Fuse A31-F3 (auxiliary B+)	5	Amp	Engine Interface board; panel lights, run and start relays
Other	Fuse A38-F1 (Network B+)	10	Amp	Governor Output Module
Other	Fuse A38-F2 (Switched B+)	10	Amp	Governor Output Module
Other	Fuse A38-F3 (Governor B+)	10	Amp	Governor Output Module
Other	Fuse TB-Bat F1 (Customer B+)	20	Amp	Engine Harness Assembly
Other	GOV RAMP adjustment range	0 through 10	seconds
Other	Governor droop adjustment range	within 5	percent of nominal frequency (3 Hz for 60Hz sets, 2.5 Hz for 50Hz sets)
Other	Governor regulation class	ISO8528 Part 1 Class G3
Other	Low oil pressure / high engine temperature fault time delay	about 10	seconds	following starter disconnect and inhibited during cranking
Other	Overcrank limit (Sentinel)	60	seconds
Other	Overcrank option limit (Detector)	75	seconds
Other	REG VHZ adjustment range	1 through 50 (normal range 7 through 21)
Other	Random frequency variation	± 0.50	%
Other	Setup/calibration menu access code	574
Other	Standard cycle cranking (Detector)	three 15-second cranking cycles with two 15-second rest periods
Other	Start delay adjustment range	0 to 300	seconds	remote starting in Auto mode
Other	Stop delay adjustment range	0 to 600	seconds	remote stopping in Auto mode
Other	Telephone Harmonic Factor (THF)	< 3	%
Other	Telephone Influence Factor (TIF)	< 50		per NEMA MG1-22.43
Other	Voltage adjustment range	±5%	%	genset running
Pressure	Actual Exhaust Back Pressure with CPG Sound level 2 Enclosure Muffler	10 (40.19) / 9.9 (39.78)	kPa (in H2O)	standby / prime
Pressure	Actual Exhaust Back Pressure with CPG Weather Enclosure Muffler	8.4 (33.76) / 7.8 (31.47)	kPa (in H2O)	standby / prime
Pressure	Engine oil pressure (normal)	30 to 65	psi (207 to 449 kPa)	at normal operating temperature
Pressure	Engine oil pressure range (low oil pressure troubleshooting)	25 to 65	psi (172 to 449 kPa)
Pressure	Fuel shutoff valve rating (TB1-8 and TB1-5)	not more than 0.5	amps	120 or 240 VAC
Pressure	Idle oil pressure	10 - 30	psi (69 - 207 kPa)	idle
Pressure	Idle oil pressure	10-30	psi (69-207 kPa)	idle
Pressure	Idle oil pressure	69-207	kPa	idle
Pressure	Idle oil pressure (normal)	10-30	psi (69-207 kPa)	Engine model 6C, idle
Pressure	Idle oil pressure shutdown limit	55	kPa	idle
Pressure	Idle oil pressure shutdown limit	8	psi (55 kPa)	idle
Pressure	Idle oil pressure warning limit	12	psi (83 kPa)	idle
Pressure	Idle oil pressure warning limit	83	kPa	idle
Pressure	Low Oil Pressure shutdown threshold	14	psi (97 kPa)
Pressure	Low oil pressure shutdown limit	14	psi (97 kPa)
Pressure	Max. Allowable Exhaust Back Pressure	41	in. H2O
Pressure	Max. Fuel Inlet Restriction	4	in. Hg (13.5 kPa)
Pressure	Max. Fuel Return Restriction	10	in. Hg (33.8 kPa)
Pressure	Max. Fuel Return Restriction	20	in. Hg (67.6 kPa)
Pressure	Maximum Air Cleaner Restriction with Clean Filter	3.7 (15)	kPa (in H2O)	clean filter

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

Fluid	Grade	Standard	Notes
Coolant		soft water/E.G./DCA mixture	Installation review checklist item: cooling system must be filled with soft water/E.G./DCA mixture.
Coolant	50/50 mix of water and antifreeze	Balanced coolant mixture of water, antifreeze and coolant additives	Drain and replace the mixture every 6 months or after 500 hours of operation. Do not add cold coolant to a hot engine; allow engine to cool below 120 F (50 C) before adding coolant.
Engine oil		Refer to Cummins engine Operation and Maintenance Manual for lubricating oil classification	Gensets are shipped with oil added.
Fuel	Diesel		Do not use zinc coated or copper fuel lines with diesel fuel.
Fuel	Number 2 diesel		Direct injection, number 2 diesel fuel
Fuel	diesel		Do not use zinc coated or copper fuel lines with diesel fuel.

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

Code	Name	Meaning	Severity	Action
101	IDLE MODE	Indicates that the engine is operating in idle mode. Grounding the engine idle input inhibits generator build-up and governs the engine at 800 RPM; control lowers oil pressure warning and shutdown trip points accordingly.	Warning	None required; removing ground returns the genset to normal speed and voltage.
102	EMERGENCY STOP	Indicates local or remote Emergency Stop.	Shutdown	Pull the button out (turn clockwise to allow it to pop out); move Run/Off/Auto switch to Off; press the Reset switch; select Run or Auto as required. Reset only at the PCC front panel.
121	SPEED SIGNAL LOST	Mag pickup speed indication is not being sensed.	Shutdown	Restart and check RPM on digital display; inspect MPU wires/connector pins; check for 3.5 to 15 VAC at MPU while cranking.
135	OIL PRESSURE SENSOR H	Engine oil pressure sender signal is shorted high.	Warning	Check sender/connectors/wires; verify fault simulation not enabled; check 0.5 to 4.5 VDC at P7-13 (OP OUT) and P7-17 (OP COM).
141	OIL PRESSURE SENSOR L	Engine oil pressure sender signal is shorted low.	Warning	Check sender/connectors/wires; check for shorts/open circuits at P7-13, 17, 21.
143	PRE-LOW OIL PRES	Engine oil pressure dropped to an unacceptable level.	Warning	Check oil level, lines and filters; replenish if low; if powering critical loads wait until next shutdown period and follow code 415.
144	COOL SENSOR HIGH	Engine coolant temperature signal is shorted high.	Warning	Check sender/connectors/wires; check resistance between P7-30 (IH20) and P7-34 (IH20 COM).
145	COOL SENSOR LOW	Engine coolant temperature signal is shorted low.	Warning	Check sender/connectors/wires; check for shorts at P7-30 and P7-34.
146	PRE-HIGH COOL TMP	Engine has begun to overheat (coolant temperature risen to an unacceptable level).	Warning	Reduce load; check air inlets/outlets and remove obstructions to airflow; if engine can be stopped follow code 151.
151	HIGH COOLANT TEMP	Engine has overheated (coolant temperature above the shutdown trip point).	Shutdown	Allow engine to cool; check coolant level; check airflow obstructions; check fan belt; check blower fan/remote radiator pumps; reset control and restart.
197	LOW COOLANT LEVEL	Engine coolant level has fallen below the warning trip point.	Warning	Allow engine to cool; check coolant level and replenish; look for leaks; reset control and restart.
200	LOW OIL PRESSURE	Indicates engine oil pressure has dropped to an unacceptable level.	Warning	If powering critical loads and cannot be shut down, wait until next shutdown period then follow the 201-SHUTDOWN procedure. Check oil pressure via the Oil Pressure menu prior to clearing the fault.
201	LOW OIL PRESSURE	Indicates engine oil pressure has dropped below the shutdown trip point.	Shutdown	Check oil level, lines and filters; if oil system is OK but oil level is low, replenish; reset control and restart. Oil pressure limits are listed in Table 4-3.
204	OIL PRES SENDER	Indicates that the control has sensed that the engine oil pressure sender is out of its working range.	Warning	Check that the engine oil pressure sender is properly connected.
210	LOW COOLANT TEMP	Warning occurs when engine coolant temperature is 70 deg F (21 deg C) or lower while set is not operating.	Warning	Indicates engine coolant heater is not operating or is not circulating coolant; check coolant heater power supply/fuse, low coolant level, and open heater element.
211	HIGH COOLANT TEMP	Indicates engine coolant temperature is getting close to the recommended maximum (215 deg F/102 deg C standby or 207 deg F/97 deg C prime).	Warning	Reduce load if possible; check air inlets and outlets and remove obstructions to airflow; if engine can be stopped follow the 212-SHUTDOWN procedure.
212	HIGH COOLANT TEMP	Indicates engine has overheated (coolant above 223 deg F/106 deg C standby or 215 deg F/102 deg C prime).	Shutdown	Allow engine to cool; check for obstructions to cooling airflow, check fan belt, check coolant mixture, check blower fan and circulation pumps; reset control and restart after correcting problem.
213	COOLANT SENDER	Indicates that the resistance of the coolant temperature sender is out of range.	Warning	Check the resistance of the sender (should be 500 to 2k ohms).
214	LOW COOLANT LVL	Indicates engine coolant level has fallen below the trip point.	Warning	Allow engine to cool; check coolant level in radiator and recovery bottle and replenish if low; check for possible coolant leakage points.
215	LOW COOLANT LVL	Indicates engine coolant level has fallen below the shutdown trip point.	Shutdown	Check coolant level in radiator and recovery bottle and replenish if low; check defective coolant bottle hose or radiator cap; reset control and restart after correcting problem. Will not occur in Idle mode.
220	MAG PICKUP	Indicates mag pickup speed indication is not being sensed or does not match generator set output frequency.	Shutdown	Restart and check RPM on the digital display; isolate per troubleshooting table 4-18.
221	FAIL TO CRANK	Indicates possible fault with control or starting system.	Shutdown	Check fuse F3 on the Engine Interface board; clean battery cable connections; recharge or replace battery.
222	OVERCRANK	Indicates possible fuel system problem.	Shutdown	Check for empty fuel tank, fuel leaks, or plugged fuel lines; check for dirty fuel filter and replace; check for dirty or plugged air filter and replace; reset control and restart.
223	OVERSPEED	Indicates engine has exceeded normal operating speed (115% +/-1% of nominal).	Shutdown	Inspect mechanical fuel linkage; check EFC for binding/damage; monitor PCC duty cycle and replace A32 or A38 as indicated.
224	FAIL TO SYNCHRONIZE	The generator set has not synchronized to the system bus within the allowable time frame.		Check governor system stability and adjust governing/synchronizer parameters; check for fuel system problems causing engine instability; widen synchronizing window and reduce acceptance time delay.
226	FAIL TO CLOSE	Indicates that the paralleling breaker has been given a signal to close, but has not closed properly.		Verify charging mechanism of paralleling breaker; check the close signal to the breaker; verify auxiliary contact signals from the breaker to the control are operational.
230	LOW DC VOLTAGE	Indicates battery voltage is below 10 VDC.	Warning	Check battery charger fuse and recharge or replace battery; clean and tighten battery cable connections; check engine DC alternator; check battery charge voltage float level.
231	HIGH DC VOLTAGE	Indicates battery voltage exceeds 32 VDC.	Warning	Check voltage float level on battery charger (lower float level); check engine DC alternator and replace if normal charging voltage is not obtained.
232	WEAK BATTERY	Indicates battery voltage drops below 60% of nominal for two seconds during starting.	Warning	Discharged or defective battery; see warning message 230, LOW DC VOLTAGE.
234	OVERSPEED	Engine has exceeded normal operating speed.	Shutdown	Clear fault and restart genset; check fault threshold; monitor RPM; check electronic governor actuator.
235	LOW COOLANT LEVEL	Engine coolant level has fallen below the shutdown trip point.	Shutdown	Check coolant level and replenish; look for leaks; reset control and restart.
240	LOW FUEL-DAY	Indicates day tank fuel supply is running low.	Warning	Check fuel supply and replenish as required.
241	LOW FUEL	Indicates fuel supply is running low.	Warning	Check fuel supply and replenish as required.
250	EEPROM ERROR	Indicates PCC memory error - data corruption of critical operating parameters.	Shutdown	Perform initial start setup; turn Run/Off/Auto to Off and reset; if the same EEPROM ERROR message occurs, replace the digital board (A32).
251	EEPROM ERROR	Indicates PCC memory error - data corruption of noncritical operating parameters.	Warning	Perform adjustment procedures and save; if the same EEPROM ERROR message occurs, replace the digital board (A32).
252	EEPROM ERROR	Indicates PCC memory error - data corruption of noncritical operating parameters.	Warning	Verify values/choices selected and repeat the save operation; if the same EEPROM ERROR message occurs, replace the digital board (A32).
260	CUSTOMER FAULT 1	Customer defined input closed to ground; message is editable.		Isolate the source of the false signal; check A34 LED corresponding to the fault input.
261	GROUND FAULT	Customer defined input closed to ground (default message); message is editable.		Isolate the source of the false signal; check A34 LED corresponding to the fault input.
262	RUPTURE BASIN (DAY TANK)	Customer defined input closed to ground; message is editable.		Isolate the source of the false signal; check A34 LED corresponding to the fault input.
263	HIGH GEN TEMP	Customer defined input closed to ground (default message); message is editable.		Isolate the source of the false signal; check A34 LED corresponding to the fault input.
270	PHASE ROTATION	The phase relationship between the generator set and the system bus is not matched.	Shutdown	Using a phase rotation checker, verify that the generator set phase rotation matches the system bus; verify control wiring to the bus PT module is properly connected.
272	FIRST START	The PowerCommand control is not receiving a proper signal from the system master first start sensor.	Warning	Control reverts to fallback mode; verify the Master First Start Sensor is functioning and that the voltage pulse is present at the PowerCommand control (terminal TB1-50); check interconnection wiring.
301	HIGH AC VOLTAGE	Indicates that one or more phase voltages has exceeded 130% of nominal, or exceeded 110% of nominal for 10 seconds.	Shutdown	Isolate the regulator module (A37), engine interface board (A31), digital board (A32), PMG/field wiring or PT/CT sensing path per troubleshooting table 4-29.
303	LOW AC VOLTAGE	Indicates that one or more phase voltages has dropped below 85% of nominal for 10 seconds.	Shutdown	Check PMG or field wiring, rotating rectifier diodes, overload, loose connectors, and voltage sensing circuitry per troubleshooting table 4-30.
313	UNDER FREQUENCY	Indicates that engine speed has dropped below 90% of nominal for 10 seconds. (Five seconds before shutdown, a Load Dump signal is initiated.)	Shutdown	Check fuel supply, intake air supply and load; check Initial Setup (set size).
320	OVERCURRENT	Indicates that generator output current has exceeded 110% of rated for 60 seconds.	Warning	Check load and load lead connections.
321	OVERCURRENT	Indicates that generator output current has exceeded 110% of rated, and a PCC time/current calculation has initiated an overcurrent shutdown.	Shutdown	Check load and load lead connections.
322	SHORT CIRCUIT	Indicates that generator output current has exceeded 175% of rated.	Shutdown	Check load and load lead connections.
330	OVERLOAD	Indicates that three-phase power output exceeds 105% of standby (or 115% of prime) rating.	Warning	Check load and load lead connections.
335	REVERSE POWER	Indicates that power is flowing into the generator set rather than out from the unit.	Shutdown	Verify connection of generator set CT's; verify proper connection of load sharing lines; verify correct frequency and voltage on all sets.
337	LOSS OF EXCITATION	Indicates that the alternator excitation system is improperly adjusted or has failed.	Shutdown	Check output voltage with calibrated meter and adjust; check load sharing lines; see Section 6 Servicing the Generator.
359	FAIL TO START	Engine cranks but fails to start (possible fuel system problem).	Shutdown	Check for empty fuel tank, fuel leaks, or plugged fuel lines; replace dirty fuel filter; replace dirty air filter; reset control and restart.
415	LOW OIL PRESSURE	Engine oil pressure has dropped below the shutdown trip point.	Shutdown	Check oil level, lines and filters; replenish if low; reset control and restart.
421	OIL TEMP	Engine has begun to overheat (oil temperature above unacceptable level) (Optional).	Warning	Reduce load; check air inlets/outlets; if engine can be stopped follow code 151 and check engine oil level.
441	LOW BAT VOLTAGE	Battery voltage supply to the control approaching a low level.	Warning	Check battery charger fuse; recharge or replace battery; clean and tighten cable connections; check engine DC alternator.
442	HIGH BAT VOLTAGE	Battery voltage supply approaching a high level at which control damage can occur.	Warning	Check float level on battery charger; check battery wiring/calibration.
1122	Rated/Idle Trans		Info
1123	SHUTDOWN AFTER BS	A shutdown fault occurred while Battle Short was enabled and transitioned from enabled to disabled.	Shutdown	Review Fault History and perform corrective action.
1124	DELAYED SHUTDOWN	A shutdown fault became active while the Delayed Shutdown feature was enabled.	Warning	Review Fault History and perform corrective action.
1131	BATTLE SHORT ACTIVE	Control is in Battle Short mode (bypasses several critical fault shutdowns).	Warning	None; used for genset operation during emergencies.
1311	Customer Input #1			Nature of fault is optional customer selection. Example inputs: Low Fuel Day Tank, Water In Fuel, Ground Fault, Low Starting Hydraulic Pressure, Low Starting Air Pressure, etc. Programmable via service tool.
1311, 1312, 1317, 1318	CUSTOMER INPUT #1 - #4	Optional customer-selected fault input is active.		Disconnect signal lead from TB1 and reset the control; check external wiring/active input selection.
1312	Customer Input #2			Nature of fault is optional customer selection. Example inputs: Low Fuel Day Tank, Water In Fuel, Ground Fault, Low Starting Hydraulic Pressure, Low Starting Air Pressure, etc. Programmable via service tool.
1317	Customer Input #3			Nature of fault is optional customer selection. Example inputs: Low Fuel Day Tank, Water In Fuel, Ground Fault, Low Starting Hydraulic Pressure, Low Starting Air Pressure, etc. Programmable via service tool.
1318	Customer Input #4			Nature of fault is optional customer selection. Example inputs: Low Fuel Day Tank, Water In Fuel, Ground Fault, Low Starting Hydraulic Pressure, Low Starting Air Pressure, etc. Programmable via service tool.
1334	CRIT SCALER OR	Incorrect feature or calibration was entered into control.	Shutdown	Reload correct feature/calibration file.
1335	NONCRIT SCALER OR	Incorrect feature or calibration was entered into control.	Warning	Reload correct feature/calibration file.
1337	No Message		Info
1416	FAIL TO SHUTDOWN	Genset continues to run after receiving shutdown command (Battle Short feature enabled).	Warning	Check Battle Short feature setting.
1417	POWER DOWN ERROR	Controller cannot power down because of an unknown condition.	Warning	Check for possible battery drain.
1433	EMERGENCY STOP	Local Emergency Stop.	Shutdown	Pull the button out; move switch to O; press Fault Acknowledge/Reset; select Manual or Auto.
1434	REMOTE E-STOP	Remote Emergency Stop.	Shutdown	See code 1433 to reset.
1435	LOW COOLANT TEMP	Engine coolant heater is not operating or not circulating coolant (coolant <=70 F [21 C]).	Warning	Check coolant heater power/fuse/cord; check coolant level; check heater element (10 to 60 ohms); check sensor.
1438	FAIL TO CRANK	Engine failed to crank after the PCC received a start signal.	Shutdown	Test for B+ at the starter; check fuse F3 (2 Amps); check K4 start pilot relay and starter circuitry; refer to code 121.
1442	WEAK BATTERY	During cranking battery voltage at or below weak battery trip point.	Warning	Recharge or replace battery; check electrolyte level and connections; check harness.
1443	BATTERY FAILED	Dead battery - engine will not start.	Shutdown	See code 1438 instructions.
1444	KW OVERLOAD	Generator output power exceeded 105% of genset rating (3 sec at 110% of rated).	Warning	Check load and load lead connections; check CTs and CT connections.
1445	SHORT CIRCUIT	Generator output current exceeded 175% of rated.	Shutdown	Check load and load lead connections (fault may not reset for several minutes).
1446	HIGH AC VOLTAGE	Phase voltage exceeded 130% of nominal, or 110% of nominal for 10 seconds.	Shutdown	Check fault simulation; clear fault and restart; refer to Generator/Base Board Isolation Procedure.
1447	LOW AC VOLTAGE	Phase voltage dropped below 85% of nominal for 10 seconds.	Shutdown	Check load; reconnect per reconnection diagram; check PMG/field wiring; check P8-21/P8-22 shunt connections.

Showing the first 80 of 110 codes.

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

Procedures

Adjusting Values/Parameters adjustment

⚠ If Home button or Previous Main Menu button is pressed before pressing save symbol, changes are not saved.

Press button next to symbol in display until + and − symbols are displayed.
Press button next to arrow symbols to move to numeric character to change.
Press button next to + symbol to increase value or select parameter.
Press button next to − symbol to decrease value or select parameter.
After adjusting values/selecting parameters, press symbol to save changes.

Convert Day Tank Controller 240 VAC to 120 VAC adjustment

Remove the two jumpers between terminals TB1-6 and TB1-7.
Connect one jumper between TB1-5 and TB1-6 and the other between TB1-7 and TB1-8.
Move selector switch S103 on the control PCB to the up position for 120V.
If equipped with a transformer, remove jumpers between H2 and H3 and connect one between H1 and H3 and the other between H2 and H4.

Day Tank Controller Conversion 240 VAC to 120 VAC adjustment

Remove the two jumpers between terminals TB1-6 and TB1-7 and connect one between TB1-5 and TB1-6 and the other between TB1-7 and TB1-8.
Move selector switch S103 on the control PCB to the up position for 120V.
On the control transformer, remove the two jumpers between terminals H2 and H3 and connect one between H1 and H3 and the other between H2 and H4.

Fuel Pump Control: Convert 120 VAC to 240 VAC adjustment

Remove jumpers between TB1-5/TB1-6 and TB1-7/TB1-8; connect two jumpers between TB1-6 and TB1-7.
Move selector switch S103 on control PCB to down position for 240 VAC.
If equipped with a transformer, remove jumpers between H1/H3 and H2/H4 and connect two jumpers between H2 and H3.
Attach a tag to the control box indicating the supply voltage.

Fuel Pump Control: Convert 240 VAC to 120 VAC adjustment

Remove jumpers between TB1-6/TB1-7; connect one jumper TB1-5 to TB1-6 and one TB1-7 to TB1-8.
Move selector switch S103 on control PCB to up position for 120V.
If equipped with a transformer, remove jumpers between H2/H3 and connect one between H1-H3 and one between H2-H4.

Governor Adjustments (Type A Electric Governor) adjustment

Set selector switch S1 to OFF, S2 to appropriate model position.
Set pots initially: Gain 20%, I 20%, D 30%, Droop 0%.
Start set, adjust Speed pot for required frequency (60Hz=1800RPM or 50Hz=1500RPM) at operating temperature.
Disconnect load, turn Gain pot to 100% or until unstable, then back off until stable.
Adjust D and I pots similarly; readjust Speed if necessary.
Push throttle to minimum speed, release and observe overshoot (2-5 Hz acceptable); adjust I pot to reduce overshoot or hunting.

Initial Start Setup adjustment

⚠ Selecting this menu resets all operating parameters to default values; perform only by technically qualified personnel.

Press RESET, MENU and PHASE SELECT simultaneously to invoke the Initial Start Setup menu.
Toggle the Standby/Prime option.
Select the correct generator set model, frequency and kW rating.
Select the correct nominal line-to-line output voltage.
Select DELTA or WYE.
Select SAVE to save changes; MAIN MENU is then displayed.

Operating PowerCommand in Droop Mode adjustment

Set the no load speed and voltage at the desired level (bus must be de-energized or disconnect Bus PT module).
Apply 100% load and adjust KW load sharing gain for desired full load frequency; adjust KVAR load sharing gain for desired full load voltage.
Repeat the process for other generator sets in the system.
Test the system with all available load and verify approximately equal load sharing at no load and maximum load.

Torque Tester / Current Transformer Installation Check adjustment

Verify the dot on the CT faces toward the generator.
Verify CT21 is on U load leads, CT22 on V load leads, CT23 on W load leads.
Verify the correct CT secondary terminal (pin 2 high voltage / pin 3 low voltage) is used.
Check CT/PT wiring if a 335 Reverse Power shutdown occurs.

Generator/Base Board Isolation Procedure diagnostic

⚠ This test involves unregulated excitation; disconnect all loads.

⚠ HAZARDOUS VOLTAGE.

Tools: Voltmeter, 12 volt battery, Jumpers

Throw line circuit breaker OFF and shut down the set.
Remove control housing side cover; disconnect exciter stator X and XX leads from AC harness.
Prepare to measure output voltage across generator terminals while set runs.
Connect a 12V battery jumper positive (+) to X lead (Field +).
Check polarity again; polarity must be correct.
Start the set and connect battery negative (-) jumper to XX lead.
If rated output voltage or higher and all phases balanced, generator is likely OK.
If unbalanced troubleshoot main stator; if uniformly low troubleshoot exciter and field circuits.

Servicing the PMG diagnostic

⚠ Touching uninsulated high voltage parts can result in severe personal injury or death.

Tools: Wheatstone bridge, digital ohmmeter

Disconnect leads P2, P3, P4 from voltage regulator.
Start engine and let speed stabilize.
Measure voltage across lead pairs P2-P3, P3-P4, P4-P2; should be at least 150 VAC (50Hz) or 180 VAC (60Hz).
Stop set and measure resistance across same lead pairs; each winding approximately 4.4 ohms.
Torque PMG rotor center bolt to 40 ft-lbs (54 Nm) when reassembling; stator leads must be at 12 o'clock.

Servicing the PMG - Testing diagnostic

⚠ HAZARDOUS VOLTAGE. Touching uninsulated high voltage parts inside the control and power output boxes can result in severe personal injury or death.

Tools: Wheatstone bridge or digital ohmmeter

Disconnect leads P2, P3 and P4 from the voltage regulator.
Start the engine at the set and let the speed stabilize.
Measure voltage across lead pairs P2-P3, P3-P4 and P4-P2 (at least 150 VAC for 50 Hz, at least 180 VAC for 60 Hz).
If voltages are low or uneven, check all leads and connections before disassembling the PMG.
Stop the set and measure electrical resistance across P2-P3, P3-P4 and P4-P2 (approximately 4.4 ohms each winding).

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

Voltage	Phase	Connection	Leads	Notes
		CT1 - U load leads (A phase); CT2 - V load leads (B phase); CT3 - W load leads (C phase)	6 lead gensets: generator output leads routed through CTs; 12 lead gensets: load wires routed through CTs	12-lead sets have dual secondary CTs (3 pins); 6-lead sets have single secondary CTs (2 pins)
		Fault relay K8/K9 (Dry Contact Module)	K8=Over Crank, Low Oil Pressure, High Engine Temperature, Low Coolant Level, Low Fuel Level; K9=Low Fuel Level, Rupture Basin	Contact ratings: 40A max carry/break N.O. 12V coil, 30A N.C. 12V coil, 20A N.O./10A N.C. 24V coil
		TB3 (ECM alternative RUN/STOP/REMOTE connection)	TB3-1=REMOTE, TB3-2=RUN, TB3-3=STOP	Provides alternative direct connection to ECM for troubleshooting or customer connection
110V - 120V L-N	Single phase, 2-wire	Jumper locations for single phase, 2-wire		PTC Module AC wiring (0300-5382-01, -02)
190, 200, 208, 220, 230, 240, 380, 416, 440, 460, 600 (L-L)	3 (three phase)	3 or 4 wires		Voltage Configuration submenu; default = 3Ph 208V 4W
190V - 240V L-L	Three phase	Jumper locations for three phase, 190V-240V L-L		Use 0300-5382-01 for 190V-240V L-L, 50/60 Hz
200, 220, 230, 240 (L-L)	1 (single phase)	3 wires		Voltage Configuration submenu (Governor/Regulator Setup)
200V - 240V L-L	Single phase, 3-wire	Jumper locations for single phase, 3-wire		PTC Module AC wiring
380V - 600V L-L	Three phase	Jumper locations for three phase, 380V-600V L-L		Use 0300-5382-02 for 380V-600V L-L, 50/60 Hz

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 6CTAA8.3 family

Part #	Description	Category
503-1134	Clamp, Hose	Clamp
V70509	Lube Oil	Fluid
155-3164-05	Muffler, Critical	Muffler
800-2072	Screw, Cap - Hex Head (M8 x 1.25 x 100)	Screw
A028Z105	Sender, Low Coolant	Sender

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 displacement of the Cummins/Onan 6CTAA8.3-G1?

The Cummins/Onan 6CTAA8.3-G1 has a displacement of 8.3 liters with 6 cylinders.

Which generators use the Cummins/Onan 6CTAA8.3-G1 engine?

The Cummins/Onan 6CTAA8.3-G1 powers 3 generator set(s), including Cummins/Onan C200 D6, Cummins/Onan C220 D5, Cummins/Onan DGFC.

What is a common problem with the Cummins/Onan 6CTAA8.3-G1 engine?

A commonly reported issue on generators using the Cummins/Onan 6CTAA8.3-G1 is: Engine cranks but will not start. Cause: Empty fuel tank, fuel leaks, or plugged fuel lines. Fix: Correct as required.