All codes
Service call
SC300
Charge corona / charge bias (older)
BPCU / developer
Level B — stop, power-cycle may clear
First check
On corona machines: wire/grid. On roller machines treat as charge leak (302).
What it means
Charge corona / charge bias (older). Confirm the exact subcode against the FSM for this serial — meaning can shift by generation.
Corona-era code. IM C uses 302/305.
Likely causes
- On corona machines: wire/grid. On roller machines treat as charge leak (302).
On-site steps
Parts to have on the truck
- Charge corona / PCU
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.