8 - 153    8 - 153
MELSEC-Q
8 TROUBLESHOOTING
*1 : Characters in parentheses ( ) indicate the special register numbers where individual information is being 
stored.
*9 : **** indicates the detected annunciator No.
*10: ***_*** indicates the detected contact and coil No.
*11 : For the Basic model QCPU, it can be turned off by the LED indication priority setting special register 
(SD207 to SD209). (Only turned off for the High Performance model QCPU, Process CPU or Redundant 
CPU.)
Error 
Code
(SD0)
*1
Error 
Messages
Common 
Information
(SD5 to 15)
Individual 
Information
(SD16 to 26)
LED Status Operating 
Statuses 
of CPU
Diagnostic 
Timing
RUN ERROR
9000 F**** 
*9
Program error 
location
Annunciator 
number
On
On/
Off 
*11
Continue
When 
instruction 
executed.
USER LED On
9010
<CHK>ERR 
***-*** 
*10
Program error 
location
Failure No.
On Off
Continue
When 
instruction 
executed.
USER LED On
9020 BOOT OK ---- ---- Off Flicker Stop
At power ON/
At reset
10000
CONT. UNIT 
ERROR
---- ---- Off Flicker Continue Always