Other Fault Code

Free · no signup

CA559

Engine bogs under load; Hard starting; Low fuel pressure warning.

System

Komatsu (VHMS)

Symptom

Engine bogs under load; Hard starting; Low fuel pressure warning.

Diagnosis & fix steps

Common Rail Fuel Pressure Low. LOGIC: The actual pressure in the fuel rail is lower than the "Commanded" pressure from the ECM. ACTION: 1. Replace fuel filters (Primary & Secondary). 2. Perform a "Cylinder Leakage Test" via the monitor. FIX: Replace a leaking Fuel Injector (internal bypass) or the High-Pressure Fuel Pump (Supply Pump).

Red Seal field insights

This is often a "Cascade Failure." If the primary pump is failing, it sends tiny metal flakes into the rail, which then wipes out all 6 injectors. Always pull the Fuel PCV (Pressure Control Valve) and check for metal glitter before just swapping filters.

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.

Track this across your whole fleet

This code is free to read. AM Fleet Integrity lets your team log fault codes against assets, plus the full fault-code library, QR operator reporting, PM scheduling and predictive alerts. Start free — no credit card required.

Start your free trial

Related Other fault codes

← All Other fault codes