Komatsu Fault Code
Free · no signupSPN 3509 FMI 3
All Digging Telemetry Lost on Dash
System
Electrical
Symptom
All Digging Telemetry Lost on Dash
Diagnosis & fix steps
LOGIC: Sensor Supply 5V Reference 1 Circuit High (Short to Power).
ACTION: Trace shared sensor harnesses to check for internal rub-through spots crossing over 24V/12V battery power lines.
Red Seal field insights
Voltage Inversion: A short circuit bridges live battery supply lines directly into a sensitive 5V reference path, shutting down internal module protection gates.
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