🚛💡 N14 Cutting In & Out? Here’s Why. David Smith asked why his N14 Cummins cuts in and out, losing power like the key is being turned off and on. ⚡🔑 On the N14, this is a very common ECM failure symptom. The engine shuts off for half a second, then kicks back on — usually because something inside the ECM is losing contact. It often throws code 343 or 111, both pointing to an internal ECM issue. 📟❗ Before replacing the ECM, always check your batteries, connections, and wiring to the ECM. Clea