Cummins Fault Code
Free · no signupCummins 111 (629-12)
No Start / No Comm.
System
Control
Symptom
No Start / No Comm.
Diagnosis & fix steps
LOGIC: ECM Internal Failure.
ACTION: Verify clean 24V power and ground to the ECM pins. If power is perfect, replace the ECM.
Red Seal field insights
RED SEAL FIX: Check the Battery Cables first! Low voltage during cranking can "corrupt" the ECM's internal boot-up, triggering 629.
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