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Cummins/Onan C30 D6 Engine

Name: Cummins/Onan C30 D6 Engine
Brand: Cummins/Onan

The Cummins/Onan C30 D6 is a 3.3 L naturally aspirated engine. It powers generator sets from Cummins/Onan.

Also known as: Cummins C30 D6

3.3 L

Displacement

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

Engine specifications

Displacement	3.3 L
Aspiration	naturally aspirated

Generator sets powered by this engine

Cummins/Onan C30 D6

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

Troubleshooting

Fault codes

Code	Meaning	Cause	Remedy
Code 135	Oil Pressure Sensor OOR - High
Code 141	Oil Pressure Sensor OOR - Low
Code 143	Engine Oil Pressure Low (Warning)
Code 144	Engine Coolant Temperature OOR Low (Warning)
Code 145	Engine Coolant Temperature OOR High (Warning)
Code 146	Engine Coolant Temperature Above Normal (Warning)
Code 151	Engine Coolant Temperature High (Shutdown)
Code 234	Engine Speed High (Shutdown)
Code 359	Engine Fail to Start
Code 415	Engine Oil Pressure Low (Shutdown)
Code 441	Low Battery Voltage
Code 442	High Battery Voltage
81 u	Generator set output frequency cannot be maintained.
59	High AC voltage shutdown (Output voltage on any phase exceeds pre-set values).
27	Low AC voltage shutdown (Voltage on any phase has dropped below a preset value).
96	Lamp: Shutdown	Indicates that the engine oil temperature is above normal and has reached the shutdown trip point.
202	Lamp: Warning	Indicates engine is operating near cooling system capacity (monitor condition). Increase in load or higher ambient temperature may cause High Coolant Temp (1) shutdown.	Review code 1 correction list for other possible causes.

Symptoms & remedies

Symptom	Cause	Remedy
Fuel contact with hot engine or exhaust		Do not permit any flame, cigarette, pilot light, spark, arcing equipment, or other ignition source near the generator set or fuel tank. Fuel lines must be adequately secured and free of leaks. Use an approved flexible line for fuel connection at the engine. Do not use copper piping on flexible lines as it will become brittle if continuously vibrated or repeatedly bent. Ensure all fuel supplies have a positive shutoff valve.
Batteries can explode		Do not dispose of the battery in a fire, because it is capable of exploding. Do not open or mutilate the battery. Do not charge frozen batteries. Batteries present the risk of high short circuit current when servicing the generator set: remove watches, rings, or other metal objects; use tools with insulated handles.
Exhaust gases are deadly		Provide an adequate exhaust system to properly expel discharged gases away from enclosed or sheltered areas, and areas where individuals are likely to congregate. Visually and audibly inspect the exhaust system daily for leaks per the maintenance schedule. Ensure that exhaust manifolds are secured and not warped. Do not use exhaust gases to heat a compartment. Make sure the unit is well ventilated.
Dizziness		IF YOU OR ANYONE ELSE EXPERIENCEANY OF THESE SYMPTOMS, GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired.
Muscular Twitching		IF YOU OR ANYONE ELSE EXPERIENCEANY OF THESE SYMPTOMS, GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired.
Vomiting		IF YOU OR ANYONE ELSE EXPERIENCEANY OF THESE SYMPTOMS, GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired.
Weakness and Sleepiness		IF YOU OR ANYONE ELSE EXPERIENCEANY OF THESE SYMPTOMS, GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired.
Inability to Think Coherently		IF YOU OR ANYONE ELSE EXPERIENCEANY OF THESE SYMPTOMS, GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired.
Output voltage on any phase exceeds pre-set values.		Values adjustable from 105-125% of nominal voltage, with time delay adjustable from 1-10 seconds. Default value is 110% for 5 seconds.
Voltage on any phase has dropped below a preset value.		Adjustable over a range of 50-95% of voltage, time delay 2-20 seconds. Default value is 90% for 5 seconds.
Low oil pressure or high coolant temperature		The control (with graphical display) will light a yellow Warning lamp or a red Shutdown lamp and display a message on the graphical display. A control without the graphical display indicates a shutdown condition by intermittent flashing of the status indicator.
Unexpected start-up or failure to crank	Remote input	Verify that the remote input is not causing the symptom or isolate the control from these inputs before troubleshooting the control.
Equipment damage due to wrong calibration file		Do not swap Baseboards from another genset model and only use the calibration file shown on the nameplate.
Features not available for troubleshooting base board		Confirm that the feature is installed and enabled prior to trouble-shooting the base board for symptoms related to a feature.
Shutdown condition		Make sure that parameter adjustments and time delays, related to the fault condition, have been appropriately set for the application. It may be necessary to write the initial capture file to the device or update the calibration file.
Shutdown or unexpected start-up		Press the button to switch to the Off mode. Turnoff or remove AC power from the battery charger. Remove the negative (–) battery cable from the generator set starting battery.
L not start in remote mode, but starts in manual mode.	The remote start switch or configurable wiring is faulty.	Reset the control. Attempt to start, and check for ground at TB1-11. If ground level is not present, isolate to the remote switch or configurable wiring. Repair as necessary. If ground is present, go to next step.
The menu display Auto button, harness or the Base board is bad.		Check for continuity between P11-16 (AUTO) to P11-8 (GND). If no continuity when pressing the menu display Auto button, isolate to front membrane panel or wiring harness. If there is continuity, the Base board is bad.
Increase in load or higher ambient temperature may cause High Coolant Temp (1) shutdown.		Review code 1 correction list for other possible causes.

Fault codes and symptom→remedy steps extracted from this engine’s service/owner documentation; verify against the official manual before servicing.

Common problems

Weakness and Sleepiness
Fix: IF YOU OR ANYONE ELSE EXPERIENCEANY OF THESE SYMPTOMS, GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired.
Vomiting
Fix: IF YOU OR ANYONE ELSE EXPERIENCEANY OF THESE SYMPTOMS, GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired.
Voltage on any phase has dropped below a preset value.
Fix: Adjustable over a range of 50-95% of voltage, time delay 2-20 seconds. Default value is 90% for 5 seconds.
Unexpected start-up or failure to crank
Cause: Remote input
Fix: Verify that the remote input is not causing the symptom or isolate the control from these inputs before troubleshooting the control.
The menu display Auto button, harness or the Base board is bad.
Fix: Check for continuity between P11-16 (AUTO) to P11-8 (GND). If no continuity when pressing the menu display Auto button, isolate to front membrane panel or wiring harness. If there is continuity, the Base board is bad.
Shutdown or unexpected start-up
Fix: Press the button to switch to the Off mode. Turnoff or remove AC power from the battery charger. Remove the negative (–) battery cable from the generator set starting battery.
Shutdown condition
Fix: Make sure that parameter adjustments and time delays, related to the fault condition, have been appropriately set for the application. It may be necessary to write the initial capture file to the device or update the calibration file.
Output voltage on any phase exceeds pre-set values.
Fix: Values adjustable from 105-125% of nominal voltage, with time delay adjustable from 1-10 seconds. Default value is 110% for 5 seconds.
Oil Pressure Sensor OOR - Low Code 141
Oil Pressure Sensor OOR - High Code 135
Muscular Twitching
Fix: IF YOU OR ANYONE ELSE EXPERIENCEANY OF THESE SYMPTOMS, GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired.
Low oil pressure or high coolant temperature
Fix: The control (with graphical display) will light a yellow Warning lamp or a red Shutdown lamp and display a message on the graphical display. A control without the graphical display indicates a shutdown condition by intermittent flashing of the status indicator.
Low Battery Voltage Code 441
Low AC voltage shutdown (Voltage on any phase has dropped below a preset value). 27
Lamp: Warning 202
Cause: Indicates engine is operating near cooling system capacity (monitor condition). Increase in load or higher ambient temperature may cause High Coolant Temp (1) shutdown.
Fix: Review code 1 correction list for other possible causes.

Compiled from service & troubleshooting documentation across every generator set that uses the Cummins/Onan C30 D6.

Service intervals

Item	Action	Hours	Months	Notes
Exhaust system	Inspect	8 hr		Visually and audibly inspect the exhaust system daily for leaks per the maintenance schedule; check for corrosion, obstruction, and leaks every time you start the generator set and every eight hours when you run it continuously
Air cleaner restriction indicator	Check	24 hr		If service indicator shows red, replace air cleaner elements and reset indicator.
Coolant heater	Check	24 hr		Verify power and operation; check for leaks.
Coolant level of radiator(s)	Check	24 hr		Top up with Cummins recommended coolant mix if low.
Engine oil level	Check	24 hr		Top up with recommended oil if low.
Fuel level in fuel tank	Check	24 hr		Refill as required.
Fuel lines and hoses	Check	24 hr		Check for leaks, worn or damaged hoses.
Generator set enclosure	Inspect	24 hr		Walk-around; ensure no inlets/outlets covered.
Operator panel operation	Check	24 hr		Check display; replace component if not functioning.
Air intake system for leaks	Inspect	50 hr		Visually inspect; check audibly when running.
Battery connections	Check	50 hr		Verify connections are secure.
Charge alternator	Check	50 hr		Check visually and audibly when running.
Coolant lines and radiator hoses	Check	50 hr		Check for leaks, wear, and cracks.
Cooling fan blades	Inspect	50 hr		Visually inspect through guarding.
Drive belt condition and tension	Check	50 hr		Check for wear or slippage.
Exhaust components and hardware	Check	50 hr		Visually inspect; check audibly when running.
Radiator air flow	Inspect	50 hr		Check for blockage, debris, wear or damage.
Engine oil and filters	Replace	200 hr		First service — After the initial 50 hour interval and every 200 hours thereafter (footnote 3).
Fuel filter and water separator	Replace	500 hr
Cooling system coolant	Replace		24 mo

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
Gap	MPU sensor tip to ring gear teeth clearance	0.5 - 0.6	mm
Other	AFLEX-H (shake table test datum)	<=3.200	g	AC156, tri-axial, 5% damping SRS
Other	AFLEX-V (shake table test datum)	<=1.333	g	AC156, tri-axial, 5% damping SRS
Other	ARIG-H (shake table test datum)	<=2.400	g	AC156, tri-axial, 5% damping SRS
Other	ARIG-V (shake table test datum)	<=0.533	g	AC156, tri-axial, 5% damping SRS
Other	Flywheel teeth (Teeth Pulses Per Revolution)	110		PCC setting
Other	Glow plug preheat time	5		glow plug calibration
Other	Glow plug total glow plug time	60		glow plug calibration
Other	Ground snow load limit	30	psf	For indoor (covered) and outdoor (exposed) installation
Other	Horizontal design seismic coefficient (z/h = 0.0)	1.440	g	Certified seismic design level, IBC Importance IP <= 1.5, Soil Classes A-E, Risk Categories I-IV, Design Categories A-F, SDS <= 2.000 g
Other	SDS (g) at z/h=1 for C10 D6 - C60 D6	2.0	g	Certified SDS, z/h = 1
Other	SDS (g) at z/h=1 for C50 D6C - C125 D6C	2.5	g	Certified SDS, z/h = 1
Other	Speed/frequency mismatch threshold	2.0	Hz	PCC setting
Other	Speed/frequency mismatch threshold time	1.5	seconds	PCC setting
Other	ZPA-H (shake table test datum)	<=2.160	g	AC156, tri-axial, 5% damping SRS
Other	ZPA-V (shake table test datum)	<=0.480	g	AC156, tri-axial, 5% damping SRS
Resistance	Battery ground connection resistance	more than 1	Ohm	indicates repair needed
Resistance	Coolant heater coil resistance	10 to 60	ohms	closed heater
Resistance	Coolant temperature sensor resistance	540 Ohms at -40 F to 1100 Ohms at 100 F; 1100 Ohms at 100 F to 1800 Ohms at 230 F	Ohm
Resistance	Diode reverse direction resistance (good)	above 20	MOhm	reverse direction at 1000 VDC
Resistance	Injection pump actuator resistance	2.3	ohms
Resistance	Main rotor resistance	0.415	Ohms	within 10% of value
Resistance	Main rotor resistance	0.437	Ohms	within 10% of value
Resistance	Main rotor resistance	0.465	Ohms	within 10% of value
Resistance	Main rotor resistance	0.545	Ohms	within 10% of value
Resistance	Main rotor resistance	0.551	Ohms	within 10% of value
Resistance	Main rotor resistance	0.657	Ohms	within 10% of value
Resistance	Main rotor resistance	0.67	Ohms	within 10% of value
Resistance	Main rotor resistance	0.708	Ohms	within 10% of value
Resistance	Main rotor resistance	0.857	Ohms	within 10% of value
Resistance	Main rotor resistance	0.89	Ohms	within 10% of value
Resistance	Main rotor resistance	0.983	Ohms	within 10% of value
Resistance	Main rotor resistance	0.99	Ohms	within 10% of value
Resistance	Main stator winding resistance	0.3	Ohms
Resistance	Main stator winding resistance	0.353	Ohms
Resistance	Main stator winding resistance	0.51	Ohms
Resistance	Main stator winding resistance	0.625	Ohms
Resistance	Main stator winding resistance	0.95	Ohms
Resistance	Main stator winding resistance	1.33	Ohms
Resistance	Main stator winding resistance	1.908	Ohms
Resistance	Starter solenoid wiring continuity (relay 87 to SW)	less than 5	Ohm
Resistance	Stator insulation resistance	1.0	Meg-Ohm	minimum to Earth (Ground)
Resistance	Temperature sender harness lead resistance	less than 0.5	Ohm	each lead from connection to PCC
Resistance	Varistor resistance (good)	greater than 100	MOhm
Resistance	Winding test conditions	20	C	winding temperature for insulation measurement
Resistance	Windings minimum insulation resistance (in-service)	5	MOhm	1 minute at 500 V test voltage
Resistance	Windings minimum insulation resistance (new)	10	MOhm	1 minute at 500 V test voltage
Speed	Frequency-to-speed gain select	30	RPM/Hz	PCC setting
Speed	Overspeed Trip Level (60 Hz)	2250		PCC threshold
Speed	Secondary Overspeed Trip Speed (60 Hz)	2250		PCC threshold
Speed	Starter Disconnect Speed	400	RPM	InPower setting
Speed	Starter Disconnect Speed (code 5134)	450	RPM	InPower setting
Temperature	High coolant temperature shutdown threshold	230 F / 110	C	shutdown
Temperature	High coolant temperature warning threshold	220 F / 105	C	warning
Temperature	Low coolant temperature warning threshold	70 F (21 C)		4BT3.3 engines
Torque	AVR cover to NDE bracket	5	Nm
Torque	AVR to NDE bracket	5	Nm
Torque	Air cleaner strap clamp	3.4 to 4.5	Nm
Torque	Alternator drive disc bolt and adaptor bolt (section 12.5)	52 +/- 5	Nm
Torque	Alternator drive disc bolts and adaptor bolts	47 to 57	Nm

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	Capacity	Notes
Coolant	50/50 coolant solution (50% pure water and 50% ethylene glycol)
Coolant	50/50 coolant solution (50% water / 50% ethylene glycol)
Engine oil	15W40		7.9 L (8.35 qt)	Refer to the Engine Operator Manual
Fuel	ASTM number 2D fuel	ASTM 2D
Fuel	Number 2 diesel fuel			Direct injection
Grease	Dow Corning silicone heat sink compound type 340 or similar			Apply to base of replacement diode only

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
1	HIGH COOLANT TEMP	Engine has overheated; coolant temperature has risen above shutdown trip point.	Shutdown	Allow engine to cool. Check coolant level, airflow obstructions, fan belt, blower and circulation pumps. Reset and restart.
12	HIGH AC VOLTAGE	One or more phase voltages exceeded 130% of nominal for 0 second, or exceeded high AC voltage threshold for time delay.	Shutdown	Check fault simulation, block load removal, threshold setting, Base board or generator, voltage sense connections.
121	Speed Signal Lost - Shutdown	No engine speed signal detected from crankshaft speed or camshaft position.	Shutdown	Inspect MPU sensor and harness; set MPU tip clearance 0.5-0.6 mm; verify calibration.
13	LOW AC VOLTAGE	One or more phase voltages dropped below low AC voltage threshold for time delay.	Shutdown	Check fault simulation, threshold, overload, output connections, excitation inputs, rotating rectifier diodes, connector or Base board.
1311	Customer Input #1	Configurable customer input 1 fault.	Warning	Check TB1-12; check external wiring; verify fault function settings.
1312	Customer Input #2	Configurable customer input 2 fault.	Warning	Check TB1-14; check external wiring; verify fault function settings.
1317	Low Coolant Level	Optional coolant level sensor indicates low coolant level.	Warning	Add coolant; check coolant level sensor connections and operation; verify calibration.
1318	Low Fuel	Optional low fuel level switch indicates low fuel.	Warning	Add fuel; verify switch operation; check wiring; verify settings.
135	Oil Pressure Sensor OOR - High	Engine oil pressure sensor signal out of range - shorted high.	Warning	Inspect sensor connections; check supply 4.75-5.25 VDC and signal voltage.
135/141	Oil Pressure Sensor OOR - Warning		Warning
14	OVER FREQUENCY	Frequency is 10% above base frequency for approximately 10 seconds.	Shutdown	Check threshold, fuel or air delivery, governor, connector or Base board.
141	Oil Pressure Sensor OOR - Low	Engine oil pressure sensor signal out of range - shorted low.	Warning	Inspect sensor connections; check supply and signal voltage.
1417	Power Down Failure	The PCC has failed to go to sleep.	Warning	Verify calibration; cycle B+ power; replace baseboard if fault persists.
143	Pre-Low Oil Pressure - Warning	Engine oil pressure below low oil pressure warning threshold (40 psig for 5 seconds).	Warning	Check oil level, external leaks, sensor accuracy, oil cooler, regulator, oil pump.
1433	Local E-Stop	State of the Local Emergency Stop has been changed.	Shutdown	Reset local E-Stop; check E-Stop switch and wiring.
1434	Remote E-Stop	State of the Remote Emergency Stop has been changed.	Shutdown	Reset remote E-Stop; install jumper TB1-16 to TB1-15; check switch and wiring.
1435	Low Coolant Temperature	Engine coolant temperature below low coolant temperature warning threshold (70 F / 21 C).	Warning	Verify LCT threshold; check coolant heater operation; check ambient temperature.
1438	Fail to Crank - Shutdown	Engine failed to crank after the generator control received a start signal.	Shutdown	Check battery, starter, starter solenoid, starter relay, CAM/Crank sense.
144	Engine Coolant Temperature OOR Low	Engine coolant temperature signal out of range - shorted low.	Warning	Inspect sensor connections; check sensor resistance; verify calibration.
1442	Weak Battery - Warning	Battery voltage dropped below weak battery voltage threshold (8 V for 2 seconds) while cranking.	Warning	Check battery, connections, charging voltage, DC alternator, harness.
1446	High AC Voltage - Shutdown	One or more phase voltages exceeded high AC voltage threshold (110% of nominal, 10 seconds).	Warning	Check threshold, PCC AVR circuit, generator output connections, PMG, EBS.
1447	Low AC Voltage - Shutdown	One or more phase voltages dropped below low AC voltage threshold (85%, 10 seconds).	Shutdown	Check AVR settings, rotating rectifier diodes, overload, residual magnetism, connections.
1448	Underfrequency	Frequency dropped below underfrequency threshold (6 Hz) for 10 seconds.	Shutdown	Check overrides, threshold, overload, engine governor.
1449	Overfrequency	Frequency went above overfrequency threshold (6 Hz) for 10 seconds.	Shutdown	Verify overfrequency threshold and time delay; check engine governor.
145	Engine Coolant Temperature OOR High	Engine coolant temperature signal out of range - shorted high.	Warning	Inspect sensor connections; check sensor resistance; verify calibration.
146	Pre-High Coolant Temp - Warning	Engine coolant temperature exceeded warning threshold (220 F / 105 C).	Warning	Check ambient temperature, coolant level, cooling components, sensor, thermostat, water pump.
1469	Speed/Hz Mismatch	Perceived engine speed and generator set output frequency do not match.	Shutdown	Check flywheel teeth (110), MPU signal, thresholds (2.0 Hz, 1.5 s), gain (30 RPM/Hz).
1471	High AC Current - Warning	Generator output current exceeded warning limit threshold (110% for 60 seconds).	Warning	Check for short, overload, CTs and CT setup, rating setup, fault override.
1472	High AC Current - Shutdown	Generator output current exceeded shutdown set limit (150% for 10 seconds).	Shutdown	Check for short/overload, CTs and CT setup, rating setup, fault override.
15	UNDER FREQUENCY	Engine speed dropped below 90% of nominal for approximately 10 seconds.	Shutdown	Check fuel supply, intake air supply, load, threshold, governor, connector or Base board.
151	High Coolant Temp - Shutdown	Engine coolant temperature exceeded shutdown threshold (230 F / 110 C).	Shutdown	Check cooling system, coolant level, sensor, thermostat, water pump.
1853	Annunciator Input 1 Fault	Customer fault 1 (input 1, LED 1) on the universal annunciator is active.	Warning	Check condition and wiring at TB1-1; verify configuration; replace annunciator if faulty.
1854	Annunciator Input 2 Fault	Customer fault 2 (input 2, LED 2) on the universal annunciator is active.	Warning	Check condition and wiring at TB1-2; verify configuration; replace annunciator if faulty.
1855	Annunciator Input 3 Fault	Customer fault 3 (input 3, LED 3) on the universal annunciator is active.	Warning	Check condition and wiring at TB1-3; verify configuration; replace annunciator if faulty.
1944	Annunciator Error - Warning	More than one network device configured to activate one annunciator output relay.	Warning	Check network configuration and devices for duplicate use of the same relay output.
2	LOW OIL PRESSURE	Engine oil pressure has dropped below shutdown trip point.	Shutdown	Check oil level, lines and filters; replenish if low; reset and restart; check oil switch.
202	PRE-HIGH COOL TMP	Engine is operating near cooling system capacity.	Warning	Review code 1 correction list.
203	LOW COOLANT TEMP	Engine coolant temperature is 70F (21C) or lower.	Warning	Check coolant heater power, low coolant level, heater element; check current draw.
204,205	CONFIGURABLE INPUT #1,#2	Optional configurable input warning.	Warning	Disconnect signal lead from TB1 and reset control; check CUST_IN1 TB1-14 and CUST_IN2 TB1-12.
212	COOL SENSOR OOR	Coolant temperature sensor output is out of range (high or low).	Warning	Check sender, connectors and wires.
213	LOW BATTERY	Battery voltage supply to control is approaching a low level.	Warning	Check battery charger fuse; recharge or replace battery; clean connections; check wiring/calibration, engine DC alternator, float level.
214	HIGH BATTERY	Battery voltage supply to control is approaching a high level.	Warning	Check float level on battery charger; check battery wiring/calibration.
215	PRE-LOW OIL PRESSURE	Engine oil pressure dropped below warning trip point.	Warning	Follow code 2 procedure.
216	HIGH AC CURRENT	One or more phase currents exceeded high AC warning threshold for time delay.	Warning	Check load and load lead connections.
217	OIL PRESS SENSOR OOR	Engine oil pressure sensor output is out of range (high or low).	Warning	Check sender, connectors and wires.
218	BATTLE SHORT ACTIVE	Control is in Battle Short mode; bypasses several fault shutdowns for emergency operation.	Warning
219	CHARGER FAILURE	Battery charging alternator has not reached acceptable voltage range within selected period (default 120 seconds).	Warning	Refer to engine service manual if fault occurs; check wiring if not failed.
220	FAIL TO SHUTDOWN	Genset continues to run after shutdown command; Battle Short feature enabled.	Warning
221	WEAK BATTERY	During cranking, battery voltage is at or below weak battery warning trip point for time >= weak battery set time.	Warning	See code 213 for corrective action.
222,223,224	ANNUNCIATOR FAULT 1,2,3	Optional configurable annunciator fault.	Warning
225	ANNUNCIATOR OUTPUT CONFIGURATION ERROR	Mismatch in configuration of one of the annunciator relay outputs.	Warning	Check network setup for duplicate use of same annunciator relay output; troubleshoot network devices.
2335	Excitation Fault - Shutdown	Control lost voltage sensing or lost zero cross sensing.	Shutdown	Check configuration, fuse F5 (10 Amp), harness connections, residual magnetism, excitation coil, control board.
234	Overspeed - Shutdown	Engine speed signals indicate engine speed greater than shutdown threshold.	Shutdown	Check MPU sensor and installation; verify overspeed trip level and flywheel teeth (110).
2676	Alternator Frequency Conflict	Alternator line frequency and alternator excitation frequency do not match.	Shutdown	Check alternator line frequency gain; check J22 and J18 connections; check harness and control board.
2677	Fail to Stop - Shutdown	Generator set continues to run after receiving shutdown command from controller.	Shutdown	Check stuck fuel actuator/fuel shutoff valve; check governor module and wiring.
27	EXCITATION FAULT	Loss of all three voltage sense leads or failure in excitation circuit.	Shutdown	Check field wiring (X1 and X2) for shorts or opens.
2729	IO Module Lost	Intermittent data link between I/O module and PCC (no input fault levels set to Shutdown).	Warning	Check AUX 101 wiring to PCC 1302; verify System IO Board Enable is disabled.
2731	IO Module Lost	Intermittent data link between I/O module and PCC (at least one input fault set to Shutdown).	Shutdown	Check AUX 101 wiring to PCC 1302; verify I/O settings.
2897	Factory Memory Block Corrupt	The control detected a corrupted memory block.	Warning	Connect with InPower 10.0+; select Initial Calibration (Recover Device).
2898	Periodic or Fault Memory Block Corrupt	The control detected a corrupted memory block.	Warning	Connect with InPower 10.0+; select Initial Calibration (Recover Device).
2899	User Memory Block Corrupt	The control detected a corrupted memory block.	Warning	Connect with InPower 10.0+; select Initial Calibration (Recover Device).
2911	Trim Memory Block Corrupt	The control detected a corrupted memory block.	Warning	Connect with InPower 10.0+; select Initial Calibration (Recover Device).
2972	Field Overload	Field AVR Duty Cycle operated at maximum output longer than Max Field Time parameter.	Shutdown	Check voltage sensing into baseboard; check AVR output; check application.
31	OVERSPEED	Engine exceeded normal operating speed; default thresholds 1725 RPM (50 Hz) or 2075 RPM (60 Hz).	Shutdown	Check cold engine, single step large block load removal, fault simulation, threshold, MPU, governor, flywheel teeth, fuel stop settings.
359	Fail to Start - Shutdown	Engine failed to start after expiration of last crank time.	Shutdown	Check flywheel teeth setting (110), starter disconnect speed (400 RPM), fuel supply, glow plugs.
38	FIELD OVERLOAD	Field AVR Duty Cycle has been at maximum for at least 15 seconds.	Shutdown
415	Low Oil Pressure - Shutdown	Engine oil pressure below low oil pressure shutdown threshold (35 psig).	Shutdown	Check oil level, external leaks, sensor accuracy, oil cooler, oil pump.
441	Low Battery Voltage	Battery voltage is low.	Warning	Check battery cables, battery condition, ground connection, DC alternator, charger.
442	High Battery Voltage	Battery voltage above high battery threshold (16 V for 60 seconds).	Warning	Verify charger set to 12 VDC; check fault threshold; check engine DC alternator.
45	SPEED SIGNAL LOST	No magnetic pickup pulses are sensed for Loss of Speed delay; if no MPU, speed sensing is by AC line frequency and fault cannot occur.	Shutdown	Inspect MPU wires/connector pins; test MPU for 3.5 to 15 VAC while cranking; check P11-12 to P11-24; replace Base board if needed.
46	HIGH AC CURRENT	Individual phase alternator output current exceeded high current threshold continuously for more than time delay.	Shutdown	Check load and load lead connections.
5134	Unknown Shutdown	PCC detected that engine RPM decreased to zero while not in run at rated mode.	Shutdown	Check calibration, air intake/exhaust restriction, MPU signal, start disconnect, fuel supply.
61	EMERGENCY STOP	Remote Emergency Stop.	Shutdown	Open (disable) remote emergency stop button; move rocker switch to OFF or press OFF; select desired operating mode.
71	SPEED HZ MATCH	Measured speed and measured AC output frequency do not agree.	Shutdown	Check genset setup for number of flywheel teeth.
72	FAIL TO CRANK	Genset failed to sense rotation for two start attempts; possible control, speed sensing or starting system fault.	Shutdown	Check starter, K7 starter relay, Emergency Stop switch/wiring, MPU circuit or Base board.
73	FAIL TO START	Engine cranks but fails to start; possible fuel system or air induction problem.	Shutdown	Check fuel tank, leaks, plugged fuel lines, fuel filter, air filter; reset and restart; check glow plugs and governor linkage.
74	FAIL TO STOP	Genset continues to run after receiving shutdown command from controller.	Shutdown
75,76	CONFIGURABLE INPUT #1 & #2	Optional configurable input fault.	Shutdown	Disconnect signal lead from TB1 and reset control; check CUST_IN1 TB1-14 and CUST_IN2 TB1-12.
77	SHUTDOWN AFTER BS	A shutdown fault occurred while Battle Short mode was enabled.	Shutdown	Check fault history for faults that may have been bypassed.
81,82,83	ANNUNCIATOR FAULT 1,2,3	Optional configurable annunciator fault.	Shutdown

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

Procedures

Disabling the AMF Feature adjustment

⚠ Must be performed by a qualified technician.

Tools: InPower service tool

Connect to the PCC 1.1 or PCC 2.3 via InPower.
Navigate to Adjustments->Features->Automatic Transfer Switch folder.
Select the Auto Mains Failure Enable parameter.
Double-click on Enabled in the Value field.
Select Disabled from the pop-up choices.
Select Device->Save Adjustments from the top menu bar.
Click Save on the confirmation pop-up.
Disconnect InPower from the PCC1302 after confirmation.

Fuel Injection Pump Speed Lever Adjustment adjustment

Make sure the generator set is off and the battery is disconnected.
If replacing pump or engine, discard speed adjust screw and tamper proof wire and seal.
Replace the low idle screw; reuse throttle screw nut and acorn nut.
Pull throttle lever back and screw new low idle screw until it contacts boss.
Continue tightening until throttle lever is locked in place.
Tighten the throttle lock nut.
Install tamper proof wire and seal.
Set the throttle lever as shown and lock it using seal wire.

Valves - Adjust, All adjustment

Disconnect battery cables
Remove valve cover
Adjust valve lash
Test run unit

Generator/Base Board Isolation Procedure diagnostic

⚠ Hazardous voltage

⚠ Test involves unregulated excitation; disconnect loads

Tools: 12 volt battery, Jumper leads, Voltmeter

Throw line circuit breaker OFF and shutdown set.
Disconnect X and XX exciter stator leads from AC harness.
Prepare to measure output voltage across generator terminals.
Bring two jumpers from 12V battery to X (Field +) and XX (Field -).
Check polarity; correct or test inconclusive.
Start set and connect battery negative to XX.
If rated output voltage or higher and balanced, generator OK; troubleshoot control.
If unbalanced, troubleshoot main stator; if uniformly low, troubleshoot exciter and field.

Testing Diodes diagnostic

⚠ Layers of dust can cause diodes to overheat and fail.

Tools: Ohmmeter

Disconnect diode pigtails from terminal posts.
Measure resistance between each diode pigtail and its plate.
Reverse meter probes and repeat.
Replace diode if resistance high or low in both directions.

Testing Exciter Rotor diagnostic

Tools: Wheatstone bridge, Ohmmeter

Disconnect six rotor winding leads from rectifier terminal posts.
Measure resistance across each pair of rotor windings U-V, V-W, W-U.
Replace whole rotor shaft assembly if any winding resistance not per Table 6-1.
Measure insulation resistance between winding lead and rotor laminations.
Replace rotor shaft assembly if insulation resistance less than 1 megohm.

Testing Exciter Stator diagnostic

Tools: Wheatstone bridge, Digital ohmmeter, Insulation resistance meter

Measure winding resistance with Wheatstone bridge or digital ohmmeter.
Replace stator if resistance not as specified in Table 6-1.
Disconnect X and XX leads and isolate from ground.
Measure resistance between either lead and stator laminations.
Replace stator if insulation resistance less than 1 megohm.

Testing Main Rotor diagnostic

Tools: Wheatstone bridge, Digital ohmmeter, Torque wrench

Disconnect two main rotor leads from rotating rectifier terminals.
Measure resistance between two leads with Wheatstone bridge or digital ohmmeter.
Replace rotor if resistance not as specified in Table 6-1.
Measure resistance between either lead and main rotor laminations.
Replace rotor if insulation resistance less than 1 megohm.
Torque terminals to 24 in-lbs (2.7 Nm) when reassembling.

Testing Main Stator diagnostic

Tools: Wheatstone bridge, Insulation tester

Measure resistance across each pair of stator leads U1-U2, U5-U6, V1-V2, V5-V6, W1-W2, W5-W6.
Use Wheatstone bridge or ohmmeter with at least 0.001 ohm precision.
Replace stator if any winding resistance not as specified in Table 6-1.
Disconnect AVR completely before insulation test.
Disconnect Neutral to Earth and any connections.
Use 500 or 1000 V insulation tester for low voltage generators up to 690V.
Minimum insulation value is 1.0 Meg-Ohm to Earth; dry windings if below.

AC Load Connections (Circuit Breaker) installation

⚠ Improper installation can lead to electrocution and property damage.

Tools: Insulated wrench, Torque wrench

Shut down and disable the generator set (Off then E-Stop, cool down).
Turn off battery charger AC and disconnect negative battery cable.
Remove enclosure side panel to access main circuit breaker box.
Place circuit breaker handle in OFF position.
Remove four bolts holding circuit breaker cover.
Connect conductors to load-side terminals, neutral lug, and grounding lug.
Torque circuit breaker terminals per breaker label.
Torque neutral lug to 31.1 Nm (275 in-lb).
Torque equipment grounding lug to 13.8 Nm (120 in-lb).
Fill stub-up openings with duct seal or mastic tape.
Install circuit breaker cover.

Connect Battery installation

⚠ Do not connect battery cables until installation is complete to prevent accidental startup.

Connect the positive battery terminal.
Connect the negative battery terminal.
Make sure black and red battery cable boots are in place.

Connecting the Battery installation

⚠ Accidental or remote starting of the generator set can cause severe personal injury or death.

Press the generator set's O (Off) button and allow it to cool.
Turn off and disconnect the battery charger from the AC source before disconnecting battery cables.
Disconnect the negative (-) cable from the battery.
Connect the positive battery terminal.
Connect the negative battery terminal.
Make sure black and red battery cable boots are in place.

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
above 300 volts L-L		X1 & X2	CT secondaries	CTs have dual secondaries (3 pins marked X1, X2 & X3).
below 300 volts L-L		X1 & X3	CT secondaries	CTs have dual secondaries (3 pins marked X1, X2 & X3).

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

Common questions

What is the displacement of the Cummins/Onan C30 D6?

The Cummins/Onan C30 D6 has a displacement of 3.3 liters.

Which generators use the Cummins/Onan C30 D6 engine?

The Cummins/Onan C30 D6 powers 1 generator set(s), including Cummins/Onan C30 D6.

What is a common problem with the Cummins/Onan C30 D6 engine?

A commonly reported issue on generators using the Cummins/Onan C30 D6 is: Weakness and Sleepiness. Fix: IF YOU OR ANYONE ELSE EXPERIENCEANY OF THESE SYMPTOMS, GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired..