QSK60 CM2358 Fault Code 1117 Power Supply Lost With Ignition On

Fault Code 1117 on a QSK60 CM2358 engine indicates a power supply issue with the ignition on. The code suggests that the supply voltage to the Engine Control Module (ECM) momentarily fell below a calibrated limit, or the ECM wasn’t allowed to power down correctly. This can lead to reduced engine performance and erratic, intermittent, or incorrect data.

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Here’s a breakdown of the key aspects of this fault and steps to troubleshoot:

Circuit Description
–  Constant Voltage Supply: The ECM receives constant voltage from the batteries via unswitched battery wires connected directly to the positive (+) battery post.
–  Switched Battery Input: This comes through the keyswitch wire when the keyswitch is turned ON.

Component Location
–  The ECM is linked to the battery by a combination of engine harness and OEM harness.
–  The exact battery location varies depending on the OEM. Refer to the OEM service manual for specifics.

Running the Diagnostics
–  This diagnostic is continuous when the keyswitch is ON or the engine is running.

Conditions for Setting the Fault Codes
–  The ECM detected that its power supply was removed before power-down parameters could be saved.
–  The fault code activates when the keyswitch is turned ON after an incomplete power-down event.

Action Taken When the Fault Code is Active
–  The ECM records the fault code immediately upon the diagnostic failure.
–  Power-down data like trip information, maintenance monitors, and fault information will not be saved when the keyswitch is turned OFF.

Clearing the Fault Code
–  Start the engine, let it idle for 1 minute, then shut it down to validate the repair.
–  The fault code status should change to INACTIVE immediately after the diagnostic passes.
–  Use the “Reset All Faults” command in the recommended Cummins® electronic service tool to clear active and inactive faults.

Shop Talk
–  ECM Unswitched Battery Supply: Ensure it comes directly from the battery, not the starter. If it’s from the starter, battery voltage could drop during cranking, setting off this fault.
–  Resistance in ECM Battery Supply Circuits: Resistance in the (+) or (-) circuits can cause voltage drops at the ECM input, activating Fault Code 1117.
–  Battery Disconnect Switches: The use of these switches can also trigger this fault.

More repair case for QSK60 CM2358, please refer to Cummins Trouble Repair