Mitsubishi Electric CITY MULTI PUHY-400YMF-B Service Handbook page 175

Checking
Meaning, detecting method
code
6606 Communications with trans-
mission processor error
Communication trouble between
apparatus processor and trans-
mission processor.
Note)
The address/attribute
shown on remote
controller indicates the
controller which has
detected error.
Cause
1) Data is not properly transmitted due
to casual errouneous operation of
the generating controller.
2) Faulty generating controller.
–172–
Checking method & Countermeasure
Turn off power sources of indoor unit and outdoor
unit.
When power sources are turned off sepa-
rately, microcomputer is not reset and nor-
mal operations can not be restored.
→ Controller trouble is the source of the trouble
when the same trouble is observed again.