Cummins/Onan DQKB Fault Codes
Troubleshooting · Updated 2026-07-01
The Cummins/Onan DQKB is a 1750 kW diesel generator. This guide explains its fault-code system, helping owners and technicians diagnose issues efficiently.
How to read Cummins/Onan DQKB fault codes
Start by reviewing operational logs for recent changes. Use the provided codes (e.g., 1311-1439) to identify problems, then safely clear them following manufacturer guidelines.
Cummins/Onan DQKB fault code list
These 15 codes are compiled from the Cummins/Onan service documentation for this model.
| Code | Symptom | Likely cause | What to do |
|---|---|---|---|
| 1311 through 1318 | Customer Defined Fault | — | — |
| 1416 | FAIL TO SHUTDOWN | — | Status ï indicates that the “Fault Bypass” mode is enabled. This mode is primarily used by service personnel for troubleshooting purposes. |
| 1417 | POWER DOWN ERROR | — | Possible drain on battery. Contact an authorized service center for service. |
| 1433 / 1434 | EMERGENCY STOP ï LOCAL / EMERGENCY STOP ï REMOTE | — | To reset the local/remote Emergency Stop button: Pull the button out. Move the O/Manual/Auto switch to O (off). Press the front panel Fault Acknowledge button. Select Manual or Auto, as required. |
| 1438 | FAIL TO CRANK | — | A. Poor battery cable connections. Clean the battery cable terminals and tighten all connections. b. Discharged or defective battery. Recharge or replace the battery. |
| 1439 | FUEL LEVEL LOW IN DAY | — | Check fuel supply and replenish as required. |
| 235 | COOLANT LEVEL ALARM | — | A. Check jacket water coolant level and replenish if low. Look for possible coolant leakage points and repair if necessary. b. Reset control and restart after locating and correcting problem. |
| 253 | OIL LEVEL ALARM | — | Check oil level, lines and filters. If oil system is OK but oil level is low, replenish. Reset control and restart. |
| 326 | OIL LEVEL WARNING | — | If generator is powering critical loads and cannot be shut down, wait until next shutdown period, then follow 688 High Oil Level Alarm procedure. If engine can be stopped follow 688 procedure. |
| 359 | ENGINE FAILED TO START | — | A. Poor battery cable connections. Clean the battery cable terminals and tighten all connections. b. Discharged or defective battery. Recharge or replace the battery. |
| 441 | LOW BATTERY VOLTAGE | — | A. Discharged or defective battery. Check the battery charger fuse. Recharge or replace the battery. b. Poor battery cable connections. Clean the battery cable terminals and tighten all connections. c. Check engine DC alternator. Replace engine DC alternator if normal battery charging voltage (24 to 26 VDC) is not obtained. d. Check float level if applicable (raise float level). |
| 442 | HIGH BATTERY VOLTAGE | — | Check float level on battery charger if applicable (lower float level). Check engine DC alternator. Replace engine DC alternator if normal battery charging voltage (24 to 26 VDC) is not obtained. |
| 471 | LOW OIL LEVEL | — | If generator is powering critical loads and cannot be shut down, wait until next shutdown period, then follow 253 Oil Level Alarm procedure. If engine can be stopped follow 253 procedure. |
| 611 | ENGINE HOT | — | This type of shutdown should be avoided. Can cause possible loss of performance and engine damage. |
| 688 | HIGH OIL LEVEL ALARM | — | Check oil level. Drain oil to operating level. |
When to call a professional
If unsure about any code or procedure, stop and contact a qualified technician immediately.
Fault codes and specifications here are compiled from manufacturer service documents. See the full Cummins/Onan DQKB specifications, engine and parts page for maintenance intervals, filters and cross-references. Always verify against the official manual for your unit.