HomeCummins/OnanCummins/Onan DXCB

Cummins/Onan DXCB Generator Set

The Cummins/Onan DXCB is a generator set powered by a Cummins/Onan 4BT3.9G2 engine. It is available at 240 V, 254 V and 277 V. It holds about 11.5 L (3.0 gal) of oil and 5.5 L (1.5 gal) of coolant, with a maximum ambient rating of 40 °C. An integrated tank holds 21 L (5.5 gal).

3.92 L
Displacement
11.5 L
Oil capacity
1
Document types

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

Service parts for the DXCB

Grouped by system, with how many of each the parts manual calls for.

Air intake

1 required

Prices captured from merchant listings; some links are affiliate links. Confirm against your serial number before ordering.

Specifications

Oil capacity11.5 L
Voltage options240 V, 254 V, 277 V
Battery voltage24 V
Battery quantity2
Coolant capacity5.5 L
Max ambient40 °C
Fuel tank21.0 L

Engine

Cummins/Onan 4BT3.9G2
Oil capacity11.0 L
Coolant capacity21.0 L
Displacement3.92 L
AspirationTurbocharged
Rated speed1800 rpm

Maintenance & consumables

for the Cummins/Onan 4BT3.9G2
ItemSpecCapacityPart #Interval
Air filterAir Filter982-0200 Amazon eBay

Common questions

Which engine powers the Cummins/Onan DXCB?

The Cummins/Onan DXCB is powered by the Cummins/Onan 4BT3.9G2 engine.

What's the oil capacity on a Cummins/Onan DXCB?

The Cummins/Onan 4BT3.9G2 engine in the Cummins/Onan DXCB has an oil capacity of 11.0 liters.

What air filter does the Cummins/Onan DXCB use?

The Cummins/Onan DXCB uses air filter part number 982-0200.

Troubleshooting

6

Symptoms & remedies

SymptomRemedy
Green RUN lamp lights following engine Start-up.Indicates all engine systems are normal. No corrective action required.
PREHI ENGINE TEMP lamp lights. Engine continues to operate.Indicates engine has begun to overheat and engine temperature has risen to approximately 220° F (105° C). If generator is powering non-critical and critical loads, and cannot be shut down, use the following: a. Reduce load if possible by turning off non-Critical loads. b. Check air inlets and outlets and remove any obstructions to airflow. c. Open doors or windows in generator area to increase ventilation. If engine can be stopped, follow procedure in step 3.
HI ENG TEMP lamp lights. Engine shuts down.Indicates engine has overheated (engine temperature has risen above 230° F/110° C) or coolant level is low (sets with coolant level sensor). Allow engine to cool down completely before proceeding with the following checks: a. Check coolant level and replenish if low. Look for possible coolant leakage points and repair if necessary. b. Check for obstructions to cooling airflow and correct as necessary. c. Check for a slipping fan belt, tighten if loose. d. Reset control and restart after locating and correcting problem. Contact your distributor if none of the above applies.
PRELO OIL PRES lamp lights. Engine continues to operate.Indicates engine oil pressure has dropped to 20 psi (138 kPa). If generator is powering critical loads and cannot be shut down, wait until next shutdown period and then follow step 5 procedure. If engine can be stopped, follow procedure in step 5.
LOOIL PRES lamp lights. Engine shuts down.Indicates engine oil pressure has dropped to 14 psi (97 kPa). Check oil level, replenish as necessary. Check oil lines and filters for leaks, repair as required. Reset control and restart. Contact your distributor if oil pressure is not in the range of 35 to 55 psi (241 to 379 kPa).
OVERCRANK lamp lights and engine stops cranking.Indicates possible fuel system problem. a. Check for empty fuel tank, fuel leaks, or plugged fuel lines and correct as required. Engine runs, shuts down, and LO OIL PRES lamp lights. b. Check for dirty fuel filter and replace if necessary (see MAINTENANCE section). c. Check for dirty or plugged air filter and replace if necessary (see MAINTENANCE section). d. Refer to step 5. e. Reset the control and restart after correcting the problem. Contact your distributor for service if none of the above applies.

Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing. Full Cummins/Onan DXCB troubleshooting guide (18 entries) →

Parts

110
Part #DescriptionQtySystem
102-1147Gasket, Drain - Oil Pan1Gasket Amazon eBay
150-2007Guard. Belt Screw. Cap - Hex Head (1/2-13 X 2-1/4“)Belt Amazon eBay FridayParts $263.79
150-2201Sensor, Speed – Magnetic1Sensor Amazon eBay
187-0001Pump, Water1Pump Amazon eBay
187-0002Gasket Kit, End - Top1Gasket Amazon eBay
187-0008Gasket, Cover - Valve1Gasket Amazon eBay
187-0009Belt, Drive4Belt Amazon eBay
187-0010Gasket, ThermostatThermostat Amazon eBay
187-0011Filter, Fuel1Fuel filter Amazon eBay $80.23
187-0012Gasket, Cover - Valve1Gasket Amazon eBay $149.89
187-0013Pump, Transfer - FuelPump Amazon eBay $100.99
187-0020Pump, Injection1Pump Amazon eBay
193-0244Sender, Pressure - 0i11Sensor Amazon eBay
193-0353Sender, Temperature - Oil1Sensor Amazon eBay
193-0375# Sender, Water Temperature1Sensor Amazon eBay
309-0269Switch, Low Engine Temperature (S4)1Sensor Amazon eBay
309-0272Regulator, Voltage - 24 VDC (Used on 35 A MP Alternator)1Alternator Amazon eBay
309-0561Alternator & Drive Components Group Pulley. Alternator - Multi Groove (Use with 35 A MP Alternator)1Oil filter Amazon eBay
328876800Belt, V-Grooved1Belt eBay
503-0098Hose, Oil Drain - Bulk (Order By The Foot - 3 Feet Required)1Hose Amazon eBay
503-0183Clamp, Hose2Hose Amazon eBay
503-0197Clip, Hose1Hose Amazon eBay $7.99
503-0685Clamp, Hose1Hose Amazon eBay $15.00
505-0059Sensor, Water Pressure1Sensor Amazon eBay
505-0104Element - Air Cleaner - Heavy Duty Primary [AM# CD1830610826]1Air filter Amazon eBay
526-0018Gasket, Flange (1-3/4)1Gasket Amazon eBay FridayParts $1002.50
960-0136Battery, 24V, 55Ah, AGM8Battery Amazon eBay
982-0200Air Filter6Air filter Amazon eBay
102-1237Adapter, Oil Drain (Ml8 x 1/2") (S2)Service part / kit Amazon eBay
145-0596Service part / kit Amazon eBay
150-2187Lever, Actuator - Governor1Service part / kit Amazon eBay
150-2203Service part / kit Amazon eBay
150-2218Service part / kit Amazon eBay
150-2251Joint, Ball2Service part / kit Amazon eBay
151-0611Control, Governor1Service part / kit Amazon eBay FridayParts $249.00
151-0632Service part / kit Amazon eBay FridayParts $315.00
154-2581Service part / kit Amazon eBay
155-2062Service part / kit Amazon eBay
155-2080Service part / kit Amazon eBay
155-2175Clamp, Muffler 4"Service part / kit Amazon eBay
155-2256Service part / kit Amazon eBay
155-2353Service part / kit Amazon eBay
187-0004Service part / kit Amazon eBay
187-0007Service part / kit Amazon eBay
187-0015Filter, Oil1Service part / kit Amazon eBay $39.95
187-0017Service part / kit Amazon eBay
187-0018Service part / kit Amazon eBay
187-0146Service part / kit Amazon eBay
187-0198Service part / kit Amazon eBay
309-0553Switch, Temperature - Pre Water1Service part / kit Amazon eBay $127.46
309-0554Switch, Temperature - Hi Water1Service part / kit Amazon eBay $159.00
323-1200# Socket, Contact (Used in J1, J2)12Service part / kit Amazon eBay
323-1304tiotming, Umector1Service part / kit Amazon eBay
323-1306Genset component (SJB series)1Service part / kit Amazon eBay
332-0051Clamp, Loop1Service part / kit Amazon eBay
332-0325Service part / kit Amazon eBay
332-0941*Tie, Cable2Service part / kit Amazon eBay
332-1087Service part / kit Amazon eBay
332-1279Terminal. Lug - Ring (3/86Service part / kit Amazon eBay
332-1445Tie. Cable1Service part / kit Amazon eBay
332-2739BracketService part / kit Amazon eBay
332-2921Switch, Temperature - Washer, Lock (M8)1Service part / kit Amazon eBay
333-0291Service part / kit Amazon eBay
333-0292Service part / kit Amazon eBay
353-0094Service part / kit Amazon eBay
357-0030# Rectifier, Silicon (CR2)1Service part / kit Amazon eBay
416-0446Cable, Battery - Jumper1Service part / kit Amazon eBay
416-0893Service part / kit Amazon eBay
416-0921Service part / kit Amazon eBay
501-0441Line, Fuel - Flex (Fuel In)1Service part / kit Amazon eBay
501-0502Line, Fuel - Flex (Fuel Out)1Service part / kit Amazon eBay
504-0011Valve, Shutoff (1/2”)1Service part / kit Amazon eBay
505-0026Coupling, Pipe (1/8")Service part / kit Amazon eBay
505-0050Elbow, Street (1/2' x 90 ° )1Service part / kit Amazon eBay
505-0098Band1Service part / kit Amazon eBay
505-0185Nipple, Half (1/2' x 1.5' lg)1Service part / kit Amazon eBay
505-1373Service part / kit Amazon eBay
526-0008Sender, Temperature - Water11Service part / kit Amazon eBay
526-0115Washer (5/16 “)2Service part / kit Amazon eBay
526-0196Washer, Spacer - Shield JC)INT, BALL LINKAGEService part / kit Amazon eBay
526-0327Service part / kit Amazon eBay
800-0012Screw, Cap - Hex Head (1/4-20 x 2-1/4”) Begin Spec C MANIFOLD KIT, INTAKE2Service part / kit Amazon eBay
800-1003Service part / kit Amazon eBay
800-2060Screw, Cap - Hex Head (M8x 1.25 x35)1Service part / kit Amazon eBay
800-2110Hood, Inlet - Air MoldedService part / kit Amazon eBay
800-2112Screw. Cap - Hex Head (M12 x 30nin)2Service part / kit Amazon eBay
812-0075Screw-RHM(8-32xl/4)Service part / kit Amazon eBay
813-0103Screw, Machine - Round Head (#10-32 x 3/4º)2Service part / kit Amazon eBay $19.00
815-0172Cover, Adapter OutletService part / kit Amazon eBay
850-0025Screw, Machine - Round Head (#8-32 x 3/8" )2Service part / kit Amazon eBay
850-0030Washer, Lock - Spring (#10)1Service part / kit Amazon eBay
850-0050Washer, Lock - Spring (3/8”)4Service part / kit Amazon eBay
850-2006Washer, Lock - Spring (M6)1Service part / kit Amazon eBay
850-2008Washer, Lock (M8)1Service part / kit Amazon eBay
850-2012Washer, Lock - Spring (M12)2Service part / kit Amazon eBay
856-0013Washer, Lock - W/EIT (1/2)1Service part / kit Amazon eBay
860-2007Circuit Breaker Used With Westinghouse Circuit Breaker1Service part / kit Amazon eBay
870-0053Nut, Hex (s10-32)1Service part / kit Amazon eBay
870-0131Nut. Hex - with ET (#10-32)2Service part / kit Amazon eBay
870-0212Nut, Locking (1/4-20)4Service part / kit Amazon eBay
871-0010Nut, Hex - Srass (#10-32) Washer, Lock - EIT (#10) Washer, Lock - IT (#10)3Service part / kit Amazon eBay
871-0028Service part / kit Amazon eBay
928-0502BService part / kit Amazon eBay
928-0506Service part / kit Amazon eBay
960-0135Service part / kit Amazon eBay $19.00
960-0242Service part / kit Amazon eBay
960-0504AService part / kit Amazon eBay
960-0505Service part / kit Amazon eBay
960-12Service part / kit Amazon eBay
965-0520Cooling Fan37Service part / kit Amazon eBay

Service, wear & replacement parts referenced for this model and its engine — confirm the exact part for your serial number. See the full parts catalog to search and cross-reference.

Available documents

Service manual — 903-0121 Onan DT and DX Models 35-100kw Operators (5-1987) (Cummins/Onan)