Sany Fault Code

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SPN 520220 FMI 03

Boom Lifts Uncommanded / Safety Cut

System

Hydraulics / Lift

Symptom

Boom Lifts Uncommanded / Safety Cut

Diagnosis & fix steps

LOGIC: Boom Raise Pilot Pressure Sensor Signal Voltage High (>4.8V). ACTION: Check 5V reference and ground at the boom pilot pressure sensor block. Inspect signal line for shorting to 5V supply or an open sensor ground wire.

Red Seal field insights

Open Ground Trap: An open ground wire floats the transducer signal to the 5.0V ceiling, causing the controller to register 100% full boom lift demand and tripping failsafe mode.

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.

Book an uptime review

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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