Cummins/Onan DQKB Fault Codes

Correct the underlying fault first, then acknowledge the code at the PowerCommand 3200 control. The documented sequence for a latched shutdown is to move the O/Manual/Auto switch to O (off) and press the front-panel Fault Acknowledge button, then select Manual or Auto as required. For an emergency-stop code (1433 local, 1434 remote) you must also pull the E-stop button back out before the acknowledge will take. Clearing a code without fixing the cause simply re-triggers it on the next start attempt.

Codes 1311 to 1318 are Customer Defined Faults. They are not built-in engine or alternator faults; they are the eight configurable customer input channels on the PowerCommand control, wired and named by whoever commissioned the set. Typical assignments are low fuel in a bulk tank, ventilation damper position, rupture-basin level or a building alarm contact. Because the meaning is site-specific, the service manual lists no cause or remedy for them: check the installation drawings for your site to find out what input 1311 through 1318 is landed on.

Both codes point at the same two documented causes, in order. First, poor battery cable connections: clean the battery cable terminals and tighten all connections. Second, a discharged or defective battery: recharge or replace it. Code 1438 means the starter never turned the engine over; code 359 means it cranked but did not fire. On a 24 V set like the DQKB, a battery that reads fine at rest but collapses under cranking load is the usual culprit, so test under load rather than at open circuit.

Code 441 has four documented causes and they should be worked in order. A discharged or defective battery: check the battery charger fuse, then recharge or replace the battery. Poor battery cable connections: clean the terminals and tighten all connections. A failed engine DC alternator: replace it if normal battery charging voltage of 24 to 26 VDC is not obtained. And an incorrect charger float level, which should be raised. Code 442 HIGH BATTERY VOLTAGE is the mirror image and is fixed by lowering the float level or replacing the same DC alternator.

They are two pairs, split by direction and by severity. On the low side, 471 LOW OIL LEVEL is the warning and 253 OIL LEVEL ALARM is the shutdown-level event: check oil level, lines and filters, and if the system is sound but the level is low, replenish, then reset the control and restart. On the high side, 326 OIL LEVEL WARNING is the warning and 688 HIGH OIL LEVEL ALARM is the alarm: check the oil level and drain to the operating level. The manual's own guidance for the warning codes is that if the generator is powering critical loads and cannot be shut down, wait until the next scheduled shutdown, then follow the matching alarm procedure.

Code 1416 indicates that Fault Bypass mode is enabled on the control. This mode is used primarily by service personnel for troubleshooting, and it deliberately suppresses the shutdown actions that would normally protect the set. Seeing 1416 on a set in normal service means someone left the control in a diagnostic state: take it out of Fault Bypass before returning the generator to automatic operation, because engine protection is compromised while it is active. The related code 1417 POWER DOWN ERROR indicates a possible drain on the battery and is a call to an authorized service centre.