Mitsubishi Electric · Split air conditioners · Mitsubishi Electric MSZ-AP (wall-mounted split, R32)
4 blinksIndoor control system
Name in the manufacturer's documentation (service manual): Indoor control system
[1]
In plain words (editorial)
Indoor control system: the indoor PCB cannot read data from its non-volatile memory. The service manual's remedy is replacing the indoor electronic control PCB.
When to call a service technician: Contact an authorised Mitsubishi Electric service technician.
✎ editorial – written from the cited sources, not a manufacturer statement. Status: draft.
For technicians
Detection conditions (source text)
- It cannot properly read data in the nonvolatile memory of the indoor electronic control P.C. board[2]
Steps given by the manufacturer (source text)
- Replace the indoor electronic control P.C. board[3]
⚠ Work on refrigerant circuits, mains electricity and PV DC wiring is for qualified technicians only.
The Polish page has more detail (plain-language explanation, safe checks, guides): Read in Polish →
Sources
Every statement has a footnote to the document and PDF page. “Quote verified” means the quote was found automatically in the text of that page.
- [1] Mitsubishi Electric – Service Manual: Indoor unit MSZ-AP25VG(K) … MSZ-AP71VG(K) (OBH788 REVISED EDITION-B) (OBH788 REVISED EDITION-B) , p. 34 official manufacturer document quote verified
4-time blink
- [2] Mitsubishi Electric – Service Manual: Indoor unit MSZ-AP25VG(K) … MSZ-AP71VG(K) (OBH788 REVISED EDITION-B) (OBH788 REVISED EDITION-B) , p. 34 official manufacturer document quote verified
memory of the indoor electronic control p.c.
- [3] Mitsubishi Electric – Service Manual: Indoor unit MSZ-AP25VG(K) … MSZ-AP71VG(K) (OBH788 REVISED EDITION-B) (OBH788 REVISED EDITION-B) , p. 34 official manufacturer document quote verified
replace the indoor electronic