What this code means

Water-in-fuel (fuel moisture) sensor feedback voltage is too high (high error). Action level L01.

Applies to: PC200-8/PC200-8M0 excavator (engine controller).

Possible causes / checks (from the source)

Komatsu South Africa customer bulletin: when CA428, CA559 and CA2249 occur, fuel line clogging or fuel contamination may be the cause.

Need the part?

If diagnosis points to a failed sensor, solenoid, controller or harness part, send us the code (CA428), machine model and serial number — we quote genuine and OEM replacement parts for export.