Mitsubishi Electric PAR-21MAA MA Remote Controller

This display indicates that there is currently no error history stored in the system's memory. This is a normal status and does not represent a fault condition.

A communication error exists within the system, potentially due to an open or shorted remote controller transmission wire (S1, S2, S3), or an outdoor unit configured with an address other than 0. The outdoor board LED shows only green after startup, and the remote controller may have no display or its display may quickly disappear.

This error indicates a communication failure within the M-NET system, affecting the exchange of data between connected M-NET devices. The specific code (A0 to A8) likely denotes different aspects or locations of the M-NET communication issue, preventing integrated system operation.

The outdoor unit has detected an error in transmitting communication signals to the indoor unit. This suggests a problem with the outdoor unit's communication circuit or the signal path, preventing it from sending operational data or control responses.

This range of codes (E0 through E5) indicates an error in the transmission of data from the remote controller, as displayed on the remote controller LCD. For specific diagnostic details regarding the root cause, further reference to the detailed error code list in the manual is required.

The remote controller itself has detected an error in receiving signals, either from other components or its own internal processes. This indicates a problem with the remote controller unit or its immediate communication line, preventing it from processing incoming data correctly.

The remote controller has detected an error in transmitting signals to the indoor unit or other system components. This indicates a problem with the remote controller's transmission circuit or its communication line, preventing it from sending control commands or status requests.

The indoor unit has detected an error in receiving signals from the remote controller. This could be due to issues with the remote controller's wiring, the indoor unit's receiving circuit, or external electrical noise disrupting the communication line.

This error indicates a communication problem between indoor and outdoor units, specifically due to incorrect wiring (converse wiring) or a complete disconnection of the communication wire. This prevents the units from exchanging essential control signals, causing system failure.

This range of codes (E6 through EF) indicates a communication error between the indoor and outdoor units, as displayed on the remote controller LCD. For specific diagnostic details regarding the root cause, further reference to the detailed error code list in the manual is required.

The indoor unit has detected an error in receiving communication signals from the outdoor unit. This indicates a problem with the data transmission path from the outdoor unit or the indoor unit's receiving circuit, leading to a loss of control and coordination.

The indoor unit has detected an error in transmitting communication signals to the outdoor unit. This suggests a problem with the indoor unit's communication circuit or the signal path itself, preventing it from sending control commands or status updates.

The outdoor unit has detected an error in receiving communication signals from the indoor unit. This indicates a problem with the data transmission path from the indoor unit or the outdoor unit's receiving circuit, leading to a loss of outdoor unit control.

The wiring between the indoor and outdoor unit, specifically for the communication lines S1, S2, S3, has incorrect polarity. This prevents the remote controller from operating and causes 'PLEASE WAIT' to be displayed. The outdoor board LED will blink green twice and red once alternately after system startup.

This communication error is detected when there is incorrect wiring of the indoor/outdoor connecting wire or if more than four indoor units are connected to the outdoor unit. This prevents proper communication and control between the indoor and outdoor units, leading to system malfunction.

The indoor unit has detected an error in transmitting signals to the remote controller. This suggests a problem with the indoor unit's communication circuit or the wiring between the indoor unit and the remote controller, preventing it from sending status updates or acknowledgments.

The wiring between the indoor and outdoor unit, specifically for the communication lines S1, S2, S3, has incorrect polarity. This prevents the remote controller from operating and causes 'PLEASE WAIT' to be displayed. The outdoor board LED will blink green twice and red once alternately after system startup.

A serial communication error has occurred either between the outdoor controller board and the outdoor power board, or between the outdoor controller board and the M-NET P.C. board. This critical internal error prevents components within the outdoor unit from communicating correctly, leading to system failure.

The outdoor unit's power supply terminals (L1, L2, L3) or communication terminals (S1, S2, S3) have incorrect connections. This prevents the remote controller from operating and keeps displaying 'PLEASE WAIT'. The outdoor board LED will blink green once and red once alternately after system startup.

A protection device connector on the outdoor unit is open, preventing proper system operation and communication. This leads to the remote controller displaying 'PLEASE WAIT'. The outdoor board LED will blink green once and red twice alternately after system startup.

A protection device connector on the outdoor unit is open, preventing proper system operation and communication. This leads to the remote controller displaying 'PLEASE WAIT'. The outdoor board LED will blink green once and red twice alternately after system startup.

A protection device connector on the outdoor unit is open, preventing proper system operation and communication. This leads to the remote controller displaying 'PLEASE WAIT'. The outdoor board LED will blink green once and red twice alternately after system startup.

The 'FFFF' display indicates that the system does not detect any applied or connected units (either indoor or outdoor). This suggests a unit might not be properly connected or is not receiving power.

The 'Fb' code indicates a general malfunction within the indoor unit, as displayed on the remote controller LCD. For specific diagnostic details regarding the root cause, further reference to the detailed error code list in the manual is required.

This range of codes (P1 through P9) indicates a general malfunction within the outdoor unit, as displayed on the remote controller LCD. For specific diagnostic details, further reference to the detailed error code list in the manual is required.

This range of codes (U1 through UP) indicates a general malfunction within the outdoor unit, as displayed on the remote controller LCD. For specific diagnostic details, further reference to the detailed error code list in the manual is required.