KIT-SWITCH 3708068 - Caterpillar

This condition indicates that the battery circuit to the Engine Control Module (ECM) has excessive voltage while the engine is running.The ECM detects the following conditions:
For 12 V systems, the battery voltage to the ECM exceeds 16 V for more than 0.5 seconds.
For 24 V systems, the battery voltage to the ECM exceeds 32 V for more than 0.5 seconds.The ECM also detects the following conditions:
The engine control is in the ON mode.
The engine is not cranking.
The engine is running.
The ECM has been powered for at least three seconds.System Response:The ECM will log the diagnostic code. The check engine lamp and the warning lamp may come on as if the ignition key switch was just turned on and the engine started.Possible Performance Effect:NoneTroubleshooting:Test Step 1. Perform the following diagnostic procedure: "Ignition Keyswitch Circuit and Battery Supply Circuit - Test"Results:
OK - STOP