RaicohField service
All codes

Service call

SC991

Software error (engine)

CController / HDD

Level C — logged only

First check

Same triage as 990, engine firmware.

What it means

Engine-side software exception.

Likely causes

  • Engine firmware
  • IOB

On-site steps

Parts to have on the truck

  • Engine firmware
  • IOB

Related codes

SC990SC998

Confirm the subcode and part number in the FSM for this serial. Raicoh is a field companion, not a replacement for the book.