Komatsu Fault Code
Free · no signupCA559 / SPN 157 FMI 18
Power Cut under Load / Stalling
System
Fuel System
Symptom
Power Cut under Load / Stalling
Diagnosis & fix steps
LOGIC: High Pressure Common Rail (HPCR) Fuel Pressure Below Threshold.
ACTION: Check primary fuel filter/water separator for restriction or air aeration. Test high-pressure pump relief valve for bypass leakage.
Red Seal field insights
Fuel Aeration: Frequently triggered in harsh operating environments due to fuel contamination, restricted filters, or air drawn past suction line cap seals.
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