Komatsu · CA778
Spare Engine Speed Sensor Failure
What this code means
Failure of the spare (backup) engine speed sensor.
Applies to: PC200-8 excavator (engine controller).
Need the part?
If diagnosis points to a failed sensor, solenoid, controller or harness part, send us the code (CA778), machine model and serial number — we quote genuine and OEM replacement parts for export.
Ask for the replacement part on WhatsAppSource: ProCarManuals – Komatsu Fault/Error Codes list (manual library). Single published source — confirm against the manual for your exact model before ordering parts. Compiled 2026-10-30. No manufacturer affiliation.