All codes
Service call
SC840
Controller ASIC / bus error
AController / HDD
Level A — stop, SP reset after repair
First check
Self-diag named a controller ASIC. Replace the controller after a re-flash fails.
What it means
Controller ASIC / bus error. Confirm the exact subcode against the FSM for this serial — meaning can shift by generation.
Likely causes
- Self-diag named a controller ASIC. Replace the controller after a re-flash fails.
On-site steps
Parts to have on the truck
- Controller
Related codes
Confirm the subcode and part number in the FSM for this serial. Raicoh is a field companion, not a replacement for the book.