Magnum Fault Code
Free · no signupAuto Sense Fail
Unit starts but shuts down immediately; "Auto Sense Fail" on screen.
System
Generator
Symptom
Unit starts but shuts down immediately; "Auto Sense Fail" on screen.
Diagnosis & fix steps
Voltage sensing failure.
LOGIC: The controller does not detect AC voltage on the sensing lines within a few seconds of startup.
ACTION: 1. Check the main breaker.
2. Inspect the Voltage Selector Switch (VSS) for solid engagement.
FIX: Clean VSS contacts; check for blown sensing fuses inside the control cabinet.
Red Seal field insights
This is often caused by the Voltage Selector Switch being "between" positions or having carbon buildup. Exercise the switch (with the unit OFF) back and forth several times to clean the contacts.
Same code keeps coming back?
That's a program problem, not a part problem. Book a 30-minute uptime review with Grant, a Red Seal Heavy Duty Technician.
Read before you touch anything
- This is general reference information, not a repair manual. It is for trained, qualified technicians.
- Fault codes, meanings and procedures vary by model, serial number and software version. Confirm the code and the procedure against the manufacturer's service manual before acting.
- Follow the OEM service manual, torque specs and your site's safety procedures: lockout/tagout, block raised equipment, relieve hydraulic, fuel and air pressure, and let hot systems cool.
- You use this information at your own risk. Adventure Mechanical and AM Fleet Integrity accept no liability for damage, injury, downtime or loss arising from its use.
- Not affiliated with or endorsed by any manufacturer. Brand names are used only to identify the equipment a code applies to.
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