Specifications
| Fuel | diesel |
|---|---|
| Controller | A1 |
| Oil capacity | 7.6 L |
| Battery voltage | 24 V |
Filters & service parts
model family| Item | Spec | Capacity | Part # | Interval | |
|---|---|---|---|---|---|
| Air filter | — | find | |||
| Fuel filter | 149-2106 | 500 hr | Amazon eBay $36.99 | ||
| Oil filter | REC1220602 | buy | |||
| Belt | — | 200 hr | find | ||
| Coolant | 2.1 | — | 1000 hr | ||
| Oil | 2.1 | — | 500 hr |
Compiled from this model's family documentation — may include parts for closely-related variants. Confirm the exact part for your serial number.
Common questions
What fuel does the Cummins/Onan MDKAZ use?
The Cummins/Onan MDKAZ runs on diesel.
What oil filter does the Cummins/Onan MDKAZ use?
The Cummins/Onan MDKAZ uses oil filter part number REC1220602.
What fuel filter does the Cummins/Onan MDKAZ use?
The Cummins/Onan MDKAZ uses fuel filter part number 149-2106.
Troubleshooting
30Fault codes
| Code | Meaning | Remedy |
|---|---|---|
| CODE NO. 15 | UNDERFREQUENCY—Engine governor unable to maintain rated frequency | 1. Reduce the number of appliances running at the same time, especially those with high motor starting loads such as air conditioners. 2. Check the fuel tank and fill as necessary. (Note: The arrangement of pickup tubes in the fuel supply tank probably is such that the genset will run out of fuel before the propulsion engines.) 3. Remove any blockage in the combustion air inlet (front grille) or exhaust system. 4. Tighten loose fuel line fittings so that air cannot be drawn in by genset lift pump suction. 5. Drain and/or replace the fuel filter (Page 16) and prime the fuel system (Page 8). 6. Drain and/or replace fuel supply system filters and prime the fuel system (Page 8). |
| CODE NO. 17 | OVER-PRIME—Prime mode exceed 5 minutes | Check for and remove any object that may be holding either control switch (remote or local) in the prime position. |
| CODE NO. 22 | GOVERNOR OVERLOAD—Maximum allowable time at full-duty cycle was exceeded | 1. Reduce the number of appliances running at the same time, especially those with high motor starting loads such as air conditioners. 2. Check the fuel tank and fill as necessary. (Note: The arrangement of pickup tubes in the fuel supply tank probably is such that the genset will run out of fuel before the propulsion engines.) 3. Remove any blockage in the combustion air inlet (front grille) or exhaust system. 4. Tighten loose fuel line fittings so that air cannot be drawn in by genset lift pump suction. 5. Drain and/or replace the fuel filter (Page 16) and prime the fuel system (Page 8). 6. Drain and/or replace fuel supply system filters and prime the fuel system (Page 8). |
| CODE NO. 23 | FAULTY OIL PRESSURE SENDER—Controller sensed grounded sender | See an authorized Onan dealer. |
| CODE NO. 24 | FAULTY TEMPERATURE SENDER—Controller sensed open sender | See an authorized Onan dealer. |
| CODE NO. 27 | LOSS OF VOLTAGE SENSE—Controller unable to sense output voltage | See an authorized Onan dealer. |
| CODE NO. 29 | HIGH BATTERY VOLTAGE—Battery system at more than 19.2 volts if 12 VDC system, or 38.4 volts if 24 volt system | 1. Check battery bank connections and reconnect if necessary to supply 12 volts or 24 volts, as appropriate. 2. Select a lower battery boost charge rate. |
| CODE NO. 35 | CONTROL CARD FAILURE—Microprocessor EEPROM error during self-test | See an authorized Onan dealer. |
| CODE NO. 36 | ENGINE STOPPED—Engine stopped without command by controller | 1. Open any closed fuel supply valves. 2. Check the fuel tank and fill as necessary. (Note: The arrangement of pickup tubes in the fuel supply tank probably is such that the genset will run out of fuel before the propulsion engines.) 3. Check for mechanical damage and service as necessary. 4. Remove any blockage in the combustion air inlet (front grille) or exhaust system. 5. Tighten loose fuel line fittings so that air cannot be drawn in by genset lift pump suction. 6. Drain and/or replace the fuel filter (Page 16) and prime the fuel system (Page 8). 7. Drain and/or replace fuel supply system filters and prime the fuel system (Page 8). |
| CODE NO. 37 | INVALID GENSET CONFIGURATION—Controller cannot determine genset operating parameters | See an authorized Onan dealer. |
| CODE NO. 38 | FIELD OVERLOAD—High field voltage induced by high rotor temperature or low power factor loads | 1. Remove blockages to generator air flow at the front inlet grill and right side, if enclosed. 2. Reduce the number of appliances running at the same time, especially those with high motor starting loads such as air conditioners. 3. Have air conditioners and other appliances checked for proper operation. (A locked compressor rotor can cause very low power factor.) |
| CODE NO. 41 | GROUNDED ROTOR—F+ grounded | See an authorized Onan dealer. |
| CODE NO. 42 | PROCESSOR FAILURE—Microprocessor ROM error during self-test | See an authorized Onan dealer. |
| CODE NO. 43 | PROCESSOR FAILURE—Microprocessor RAM error during self-test | See an authorized Onan dealer. |
| CODE NO. 48 | PROCESSOR FAILURE—Controller unable to sense field voltage | See an authorized Onan dealer. |
| CODE NO. 58 | HIGH EXHAUST TEMPERATURE—Exhaust temperature exceeded design limits | 1. Check for and reconnect or replace any disconnected or leaking raw water hoses (Page 19). 2. Check for a and replace a worn raw water impeller(Page 23) |
| 1 | HIGH ENGINE TEMPERATURE | 1. Add coolant as necessary and repair leaks (Page 18). 2. Replace the engine thermostat, which might not be opening fully (Page 21). 3. Clean the raw water tubes in the heat exchanger, which might be clogged with scale (Page 22). 4. Flush the coolant system to remove coolant passage fouling (Page 18). |
| 2 | LOW OIL PRESSURE | Add engine oil or drain excess oil, as necessary (Page 14). |
| 3 | SERVICE CHECK | Check the second-level shutdown code by pressing STOP once. The second-level shutdown code will have two-digits. The shutdowns are listed below in numerical order. |
| 4 | OVERCRANK | 1. Check the fuel tank and fill as necessary. (Note: The arrangement of pickup tubes in the fuel supply tank probably is such that the genset will run out of fuel before the propulsion engines.) 2. Open any closed fuel valves. 3. Remove any blockage in the combustion air inlet (front grille) or exhaust system. 4. Tighten loose fuel line fittings so that air cannot be drawn in by genset lift pump suction. 5. Drain and/or replace the fuel filter (Page 16) and prime the fuel system (Page 8). 6. Drain and/or replace fuel supply system filters and prime the fuel system (Page 8). |
| 7 | LOSS OF RAW WATER FLOW | 1. Open the sea cock. 2. Close the sea cock and clean the sea water strainer. If the strainer is above the water line, fill it with water to assist priming. Secure the strainer cover and reopen the sea cock. 3. Reconnect or replace any disconnected or leaking raw water hoses (Page 19). 4. Remove any blockage from the strainer on the through-hull fitting on the bottom side of the hull. 5. Replace the raw water impeller (Page 23). |
| 12 | OVERVOLTAGE | See an authorized Onan dealer. |
| 13 | UNDERVOLTAGE | Reduce the number of connected appliances, especially when air conditioners and battery chargers are running. |
| 14 | OVERFREQUENCY | 1. If the line circuit breaker or any other circuit breaker has tripped, start the genset before resetting the breaker. (Frequency can overshoot when a circuit breaker trips under load.) If the genset continues to run, turn off or disconnect all loads, reset the breaker and bring the loads on one at a time without overloading the genset. 2. Tighten loose fuel line fittings so that air cannot be drawn in by genset lift pump suction. 3. Prime the fuel system to remove air in the fuel lines (Page 8). |
Symptoms & remedies
| Symptom | Cause | Remedy |
|---|---|---|
| The genset fails to start | Cranking will discontinue in 20 to 60 seconds, depending on how cold the engine is, and the amber status lamp will blink Shutdown Code No. 4 (Page 7-5). See Troubleshooting (Page 7-1) if the genset does not start after two or three tries. | |
| The genset shuts down | See Troubleshooting (Page 7-1). | |
| STARTER ENGAGES-DISENGAGES | (Battery voltage dips below 6 volts while cranking—low battery charge, poor connections, long cables) | 1. Clean and tighten the positive (+) and negative (- ) battery cable connections at the battery and gen-set (Page 17). 2. Recharge or replace the battery. Refer to the battery manufacturer’s recommendations. 3. Increase battery cable size or run parallel cables. |
| RUN-DOWN STARTING BATTERY | (Marginal battery, connections, or charging system or, parasitic loads) | 1. Clean and tighten the positive (+) and negative (- ) battery cable connections at the battery and gen-set (Page 17). 2. Recharge or replace the battery. Refer to the battery manufacturer’s recommendations. |
| ENGINE CRANKS, STARTS, ACCELERATES, BUT STOPS WHEN SWITCH LET GO | (Open field or open or grounded quadrature circuit) | Corrective Action: See an authorized Onan dealer. |
| NO LIGHTS, NO RESPONSE | (Poor connections, faulty wiring or dead battery) | 1. Try the genset Control Switch if the remote Control Switch does not work, and vice versa. 2. Clean and tighten the positive (+) and negative (- ) battery cable connections at the battery and gen-set (Page 17). 3. Recharge or replace the battery. Refer to the battery manufacturer’s recommendations. |
Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing.
Repair guides
2Step-by-step procedures compiled from the Cummins/Onan service manual for this model.
Parts
7| Part # | Description | Qty | System | |
|---|---|---|---|---|
| 122-0810 | Oil Filter | 1 | Oil filter | Amazon eBay $36.45 |
| 132-0415 | Pump Impeller | 1 | Impeller | buy |
| 149-2106 | Fuel Filter Element | 1 | Fuel filter | Amazon eBay $36.99 |
| 185-7055 | Cruise Kit | 2 | Cruise kit | buy |
| 511-0201 | V-Belt | 1 | Belt | Amazon eBay |
| 130-4434 | Zinc Pencil | 1 | Service part / kit | eBay $32.94 |
| 185-5523 | Crankcase Breather | 1 | Service part / kit | buy |
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.
Fuel consumption
| Rating | Load | L/h | gal/h |
|---|---|---|---|
| Prime | |||
| Standby |
Available documents
Operator's manual — 981-0163B Cummins MDKAV - MDKAZ MDKBD - MDKBG Operator's Manual (6-2002) (Cummins/Onan)Parts manual — 981-0268 Onan MDKAV MDKAW MDKAZ Parts Manual (6-2014) (Cummins/Onan)Parts manual — NET-Onan (Cummins/Onan)Service manual — 900-0624 Onan MDKAV - MDKBN Repair Times (Cummins/Onan)Service manual — 981-0534B Onan MDKAV thru MDKAZ MDKBD thru MDKBG Service Manual (6-2002) (Cummins/Onan)Service manual — 981-0630C Onan MDKAV thru MDKBG Installation Manual (2-2004) (Cummins/Onan)Service manual — eqdpartscard (Cummins/Onan)