Service manual

Service Call Conditions
SM 6-29 M052/M053/M054
Trouble-
shooting
991 C Software continuity error
The software attempted to perform
an unexpected operation. However,
unlike SC990, the object of the error
is continuity of the software.
 No operation required.
Note: This SC code does not
appear on the panel, and is only
logged.
992 D Unexpected Software Error
Software encountered an unexpected
operation not defined under any SC
code.
 Software defective
 An error undetectable by any
other SC code occurred