40 / E40
Control determines its compressor requirement is different than the compressor capability
This code typically points to
- Memory card not correct
- Control board mismatch
Next checks to confirm
- Check memory-card data versus outdoor unit model
- Verify control-board size versus outdoor unit model
- Replace control board if necessary
Escalation
Unit capability mismatch / operation inhibited
Reset behavior
Clears after correct data/control is installed.
Urgent
Fix now