Mitsubishi Electric mini-split blink codes and error codes
57 codes for GL, FS, FH, GS06–24, GS30/36, PKA-A KA8, PKA-A LA1, PLA-A EA8, each with the wording and page from Mitsubishi Electric's manuals.
All Mitsubishi Electric codes
Meanings are quoted from Mitsubishi Electric's manuals. The "Who" column is our reading of themanual's remedy: whether an owner can do the first checks, or the fix belongs to a licensed technician.
| Code | Manual meaning | Series | Who | Source |
|---|---|---|---|---|
| 0.5 s ON / 0.5 s OFF | “Miswiring or serial signal” Indoor unit OPERATION INDICATOR lamp, table 9-4: a steady blink, 0.5 second on and 0.5 second off. Indoor and outdoor units do not operate. Condition: “The serial signal from the outdoor unit is not received for 6 minutes.” (GS30/36: “for a maximum of 6 minutes”, MSZ-GS Indoor Service Manual OBH874A, p. 39). During the installer's 30-minute test run, the installation manuals say to inspect the indoor/outdoor connecting wire if the lamp blinks every 0.5 seconds (MSZ-GL Installation Manual, p. 7; MSZ-FS Installation Manual, p. 7; MSZ-FH Installation Manual, p. 7; MSZ-GS Installation Manual, section 4-2 Test Run). | GL, FS, FH, GS06–24, GS30/36 | Technician | GL indoor service p. 27; FS indoor service p. 24; FH indoor service p. 24; GS indoor service p. 38; GS indoor service p. 39 |
| 2 blinks | “Indoor coil thermistor / Room temperature thermistor” Indoor lamp, table 9-4: 2 blinks, then 2.5 seconds off. Indoor and outdoor units do not operate. Condition: “The indoor coil or the room temperature thermistor is short or open circuit.” | GL, FS, FH, GS06–24, GS30/36 | Technician | GL indoor service p. 27; FS indoor service p. 24; FH indoor service p. 24; GS indoor service p. 38; GS indoor service p. 39 |
| 3 blinks | “Indoor fan motor” Indoor lamp, table 9-4: 3 blinks, then 2.5 seconds off. Indoor and outdoor units do not operate. Condition: “The rotational frequency feedback signal is not emitted during the indoor fan operation.” | GL, FS, FH, GS06–24, GS30/36 | Technician | GL indoor service p. 27; FS indoor service p. 24; FH indoor service p. 24; GS indoor service p. 38; GS indoor service p. 39 |
| 4 blinks | “Indoor control system” Indoor lamp, table 9-4: 4 blinks, then 2.5 seconds off. Indoor and outdoor units do not operate. Condition: “It cannot properly read data in the nonvolatile memory of the indoor electronic control P.C. board.” The table's remedy is to replace that board. | GL, FS, FH, GS06–24, GS30/36 | Technician | GL indoor service p. 27; FS indoor service p. 24; FH indoor service p. 24; GS indoor service p. 38; GS indoor service p. 39 |
| 5 blinks | “Outdoor power system” What to check Indoor lamp, table 9-4: 5 blinks, then 2.5 seconds off; the upper lamp on GL and GS06–24, the left lamp on FS, FH and GS30/36. Indoor and outdoor units do not operate. Condition: “It consecutively occurs 3 times that the compressor stops for overcurrent protection or startup failure protection within 1 minute after startup.” | GL, FS, FH, GS06–24, GS30/36 | Technician | GL indoor service p. 27; FS indoor service p. 24; FH indoor service p. 24; GS indoor service p. 38; GS indoor service p. 39 |
| 6 blinks | “Outdoor thermistors” Indoor lamp, table 9-4: 6 blinks, then 2.5 seconds off. Indoor and outdoor units do not operate. Condition: “The outdoor thermistors short or open circuit during the compressor operation.” | GL, FS, FH, GS06–24, GS30/36 | Technician | GL indoor service p. 27; FS indoor service p. 24; FH indoor service p. 24; GS indoor service p. 38; GS indoor service p. 39 |
| 7 blinks | “Outdoor control system” Indoor lamp, table 9-4: 7 blinks, then 2.5 seconds off. Indoor and outdoor units do not operate. Condition: “It cannot properly read data in the nonvolatile memory of the inverter P.C. board or the outdoor electronic control P.C. board.” | GL, FS, FH, GS06–24, GS30/36 | Technician | GL indoor service p. 27; FS indoor service p. 24; FH indoor service p. 24; GS indoor service p. 38; GS indoor service p. 39 |
| 14 blinks or more | “Other abnormality” What to check Indoor lamp, table 9-4: 14 or more blinks, then 2.5 seconds off; the GS30/36 table prints “14-time blink” (MSZ-GS Indoor Service Manual OBH874A, p. 39). Indoor and outdoor units do not operate. GL and FH: “An abnormality other than above mentioned is detected.” FS adds the indoor, defrost or ambient temperature thermistors; GS adds the indoor or ambient temperature thermistors; in table 9-4 of these two manuals the row also says not to start the unit again without repair (MSZ-FS Indoor Service Manual OBH872A, p. 24; MSZ-GS Indoor Service Manual OBH874A, pp. 38–39). | GL, FS, FH, GS06–24, GS30/36 | Technician | GL indoor service p. 27; FS indoor service p. 24; FH indoor service p. 24; GS indoor service p. 38; GS indoor service p. 39 |
| Upper/left lamp lights up | “Outdoor control system” Table 9-4: the lamp stays lit (upper lamp on GL and GS06–24, left lamp on FS and FH) and the outdoor unit does not operate. Condition: nonvolatile memory data of the inverter P.C. board or the outdoor electronic control P.C. board cannot be read; the remedy is to read the LED on that board. A lit lamp on its own is not this code: the GL and FS owner's lamp charts show the lamp lit while the unit runs (MSZ-GL Operating Instructions, p. En-5; MSZ-FS Operating Instructions, p. En-6). The GS30/36 table has no such row. | GL, FS, FH, GS06–24 | Technician | GL indoor service p. 27; FS indoor service p. 24; FH indoor service p. 24; GS indoor service p. 38 |
| Upper lamp lights, lower lamp blinks | “MXZ type Operation mode setting” Table 9-4, for an indoor unit on an MXZ multi-zone outdoor unit: the outdoor unit operates but this indoor unit does not. Condition: indoor units are set to COOL (including DRY) and HEAT at the same time, and the unit that started first has priority; the remedy is “Unify the operation mode.” The owner's lamp charts list a standby mode during multi-system operation (MSZ-GL Operating Instructions, p. En-5). | GL, GS30/36 | Technician | GL indoor service p. 28; GS indoor service p. 39 |
| LED 1 blink every 2.5 s | “Outdoor power system” LED on the outdoor unit's inverter P.C. board, table 10-3. The outdoor unit does not operate. Condition: “Overcurrent protection cut-out operates 3 consecutive times within 1 minute after the compressor gets started.” The table prints the same LED pattern for outdoor thermistors and outdoor control system. | GL, FS, FH, GS06–24, GS30/36 | Technician | GL outdoor service p. 46; FS outdoor service p. 30; FH outdoor service p. 34; GS outdoor service p. 64 |
| LED 1 blink every 2.5 s | “Outdoor thermistors” Outdoor board LED, table 10-3. The outdoor unit does not operate. A discharge, fin, defrost, P.C. board, outdoor heat exchanger or ambient temperature thermistor shorts or opens during compressor running. FS and GS give the P.C. board temperature thermistor its own line, with the remedy to replace the inverter P.C. board (MUZ-FS Outdoor Service Manual OBH873B, p. 30; MUZ-GS Outdoor Service Manual OBH875B, p. 64). | GL, FS, FH, GS06–24, GS30/36 | Technician | GL outdoor service p. 46; FS outdoor service p. 30; FH outdoor service p. 34; GS outdoor service p. 64 |
| LED 1 blink every 2.5 s | “Outdoor control system” Outdoor board LED, table 10-3. The outdoor unit does not operate. Condition: “Nonvolatile memory data cannot be read properly.” The table adds that the indoor unit's OPERATION INDICATOR lamp lights up or blinks 7 times (the upper lamp in the MUZ-GL outdoor manual, the left lamp in the MUZ-FS, MUZ-FH and MUZ-GS outdoor manuals). | GL, FS, FH, GS06–24, GS30/36 | Technician | GL outdoor service p. 46; FS outdoor service p. 30; FH outdoor service p. 34; GS outdoor service p. 64 |
| LED 6 blinks | “Serial signal” Outdoor board LED, table 10-3. The outdoor unit does not operate. Condition: “The communication fails between the indoor and outdoor unit for 3 minutes.” The indoor lamp table uses 6 minutes for its 0.5 s blink (MSZ-GL Indoor Service Manual OBH732D, p. 27). On FH15/18 the remedy adds a check of the connection between the inverter and relay P.C. boards (MUZ-FH Outdoor Service Manual OBH684E, p. 34). | GL, FS, FH, GS06–24, GS30/36 | Technician | GL outdoor service p. 46; FS outdoor service p. 30; FH outdoor service p. 34; GS outdoor service p. 64 |
| LED 11 blinks | “Stop valve/ Closed valve” Outdoor board LED, table 10-3. The outdoor unit does not operate. Condition: “Closed valve is detected by compressor current.” Remedy: check the stop valve. | GL, FS, FH, GS06–24, GS30/36 | Technician | GL outdoor service p. 46; FS outdoor service p. 30; FH outdoor service p. 34; GS outdoor service p. 64 |
| LED 16 blinks | “4-way valve/ Pipe temperature” Outdoor board LED, table 10-3. The outdoor unit does not operate. Condition: the 4-way valve does not work properly and the indoor coil thermistor detects an abnormal temperature. Remedy: check the R.V. coil, replace the inverter P.C. board. | GL, FS, FH, GS06–24, GS30/36 | Technician | GL outdoor service p. 46; FS outdoor service p. 30; FH outdoor service p. 34; GS outdoor service p. 64 |
| LED 17 blinks | “Outdoor refrigerant system abnormality” What to check Outdoor board LED, table 10-3. The outdoor unit does not operate. Condition: “A closed valve and air trapped in the refrigerant circuit are detected based on the temperature sensed by the indoor and outdoor thermistors and the current of the compressor.” The remedy starts with a check for a gas leak in the connecting piping. The “Check of outdoor refrigerant circuit” procedure in all four outdoor manuals prints “CAUTION : Do not start the operation again to prevent hazards.” (MUZ-GL Outdoor Service Manual OBH733J, p. 59; MUZ-FS Outdoor Service Manual OBH873B, p. 42; MUZ-FH Outdoor Service Manual OBH684E, p. 46; MUZ-GS Outdoor Service Manual OBH875B, p. 79). | GL, FS, FH, GS06–24, GS30/36 | Technician | GL outdoor service p. 46; FS outdoor service p. 30; FH outdoor service p. 34; GS outdoor service p. 64 |
| LED 2 blinks | “Overcurrent protection” Outdoor board LED, table 10-3. “Outdoor unit stops and restarts 3 minutes later” is repeated. Condition: large current flows into the power module (the IGBT module on MUZ/MUY-GL24 and MUZ-FH15/18). | GL, FS, FH, GS06–24, GS30/36 | Technician | GL outdoor service p. 46; FS outdoor service p. 30; FH outdoor service p. 34; GS outdoor service p. 64 |
| LED 3 blinks | “Discharge temperature overheat protection” Outdoor board LED, table 10-3. The stop and restart 3 minutes later repeats. Condition: the discharge temperature thermistor exceeds 241°F (116°C) and the compressor stops; it can restart if the thermistor reads 212°F (100°C) or less 3 minutes later. | GL, FS, FH, GS06–24, GS30/36 | Technician | GL outdoor service p. 46; FS outdoor service p. 30; FH outdoor service p. 34; GS outdoor service p. 64 |
| LED 4 blinks | “Fin temperature /P.C. board temperature thermistor overheat protection” Outdoor board LED, table 10-3. The stop and restart 3 minutes later repeats. Condition: the fin or P.C. board temperature thermistor exceeds a model-dependent limit, such as 167–187°F (75–86°C) for the fin on MUZ-GL09/12/15/18. The remedy starts with checking around the outdoor unit and its air passage. | GL, FS, FH, GS06–24, GS30/36 | Technician | GL outdoor service p. 46; FS outdoor service p. 30; FH outdoor service p. 34; GS outdoor service p. 64 |
| LED 5 blinks | “High pressure protection” Outdoor board LED, table 10-3. The stop and restart 3 minutes later repeats. Condition: the indoor coil thermistor exceeds 158°F (70°C) in HEAT mode, or the defrost thermistor exceeds 158°F (70°C) in COOL mode. | GL, FS, FH, GS06–24, GS30/36 | Technician | GL outdoor service p. 46; FS outdoor service p. 30; FH outdoor service p. 34; GS outdoor service p. 64 |
| LED 8 blinks | “Compressor synchronous abnormality” Outdoor board LED, table 10-3. The stop and restart 3 minutes later repeats. Condition: “The waveform of compressor current is distorted.” While the outdoor unit keeps running, the same LED count means PAM protection or zero cross detecting circuit, depending on the model. | GL, FS, FH, GS06–24, GS30/36 | Technician | GL outdoor service p. 46; FS outdoor service p. 30; FH outdoor service p. 34; GS outdoor service p. 64 |
| LED 10 blinks | “Outdoor fan motor” Outdoor board LED, table 10-3. The stop and restart 3 minutes later repeats. Condition: the outdoor fan has stopped 3 times in a row within 30 seconds after it starts. | GL, FS, FH, GS06–24, GS30/36 | Technician | GL outdoor service p. 46; FS outdoor service p. 30; FH outdoor service p. 34; GS outdoor service p. 64 |
| LED 12 blinks | “Each phase current of compressor” Outdoor board LED, table 10-3. The stop and restart 3 minutes later repeats. Condition: “Each phase current of compressor cannot be detected normally.” | GL, FS, FH, GS06–24, GS30/36 | Technician | GL outdoor service p. 46; FS outdoor service p. 30; FH outdoor service p. 34; GS outdoor service p. 64 |
| LED 13 blinks | “Bus-bar voltage (DC)” Outdoor board LED, table 10-3. The stop and restart 3 minutes later repeats. Condition: the inverter's bus-bar voltage cannot be detected normally. FH calls it “DC voltage” (MUZ-FH Outdoor Service Manual OBH684E, p. 34). The remedy names an instantaneous power voltage drop (short time power failure) as one case: for GL24, FS15/18 and FH15/18 in those tables, with no model limit on GS. | GL, FS, FH, GS06–24, GS30/36 | Technician | GL outdoor service p. 46; FS outdoor service p. 30; FH outdoor service p. 34; GS outdoor service p. 64 |
| LED 1 blink | “Frequency drop by current protection” Outdoor board LED, table 10-3: 1 blink, then 2.5 seconds off, while the outdoor unit operates. The compressor frequency is lowered when input current exceeds about 10 A or 10.5 A, or, on GL24, FS15/18, FH15/18, GS18NAHZ and GS24/30/36, when current from the power outlet is nearing breaker capacity. The table says the unit is normal but lists checks for clogged indoor filters, a refrigerant shortage and short-cycled air. GS: “Deceleration of the operational frequency of the compressor by the current protection control” (MUZ-GS Outdoor Service Manual OBH875B, p. 65). | GL, FS, FH, GS06–24, GS30/36 | Technician | GL outdoor service p. 47; FS outdoor service p. 31; FH outdoor service p. 35; GS outdoor service p. 65 |
| LED 3 blinks | “Frequency drop by high pressure protection” Outdoor board LED, table 10-3, while the outdoor unit operates. The compressor frequency is lowered when the indoor coil thermistor exceeds 131°F (55°C) in HEAT mode; the same row covers COOL mode, when the indoor coil thermistor reads 46°F (8°C) or less. GS: “Deceleration of the operational frequency of the compressor by the high pressure protection” (MUZ-GS Outdoor Service Manual OBH875B, p. 65). | GL, FS, FH, GS06–24, GS30/36 | Technician | GL outdoor service p. 47; FS outdoor service p. 31; FH outdoor service p. 35; GS outdoor service p. 65 |
| LED 4 blinks | “Frequency drop by discharge temperature protection” Outdoor board LED, table 10-3, while the outdoor unit operates. The compressor frequency is lowered when the discharge temperature thermistor exceeds 232°F (111°C). GS: “Deceleration of the operational frequency of the compressor by the discharge temperature protection” (MUZ-GS Outdoor Service Manual OBH875B, p. 65). | GL, FS, FH, GS06–24, GS30/36 | Technician | GL outdoor service p. 47; FS outdoor service p. 31; FH outdoor service p. 35; GS outdoor service p. 65 |
| LED 5 blinks | “Outside temperature thermistor protection” Outdoor board LED, table 10-3, while the outdoor unit operates. When the outside temperature thermistor shorts or opens, the unit runs a protective operation without it. Printed for MUZ-FS06/09/12, MUZ-FH06/09/12 and MUZ-GS09/12/15/18; the GL table gives no model limit. | GL, FS, FH, GS06–24 | Technician | GL outdoor service p. 47; FS outdoor service p. 31; FH outdoor service p. 35; GS outdoor service p. 65 |
| LED 7 blinks | “Low discharge temperature protection” Outdoor board LED, table 10-3, while the outdoor unit operates. Condition: the discharge temperature thermistor has read 122°F (50°C) or less for 20 minutes. | GL, FS, FH, GS06–24, GS30/36 | Technician | GL outdoor service p. 47; FS outdoor service p. 31; FH outdoor service p. 35; GS outdoor service p. 65 |
| LED 8 blinks | “PAM protection (PAM: Pulse Amplitude Modulation)” Outdoor board LED, table 10-3, while the outdoor unit operates. Printed for MUZ/MUY-GL09/12/15/18, MUZ-FS06/09/12 and MUZ-FH06/09/12. The table says “This is not malfunction.” and names an instantaneous power voltage drop or a high supply voltage as the cases. | GL, FS, FH | Technician | GL outdoor service p. 47; FS outdoor service p. 31; FH outdoor service p. 35 |
| LED 8 blinks | “Zero cross detecting circuit” Outdoor board LED, table 10-3, while the outdoor unit operates. Printed for MUZ/MUY-GL24, MUZ-FS15/18 and MUZ-FH15/18; the GS table gives no model limit. Condition: “Zero cross signal cannot be detected.” Cases listed: an instantaneous power voltage drop or distortion of the primary voltage. | GL, FS, FH, GS06–24, GS30/36 | Technician | GL outdoor service p. 47; FS outdoor service p. 31; FH outdoor service p. 35; GS outdoor service p. 65 |
| LED 9 blinks | “Inverter check mode” What to check Outdoor board LED, table 10-3, while the outdoor unit operates. Condition: “The connector of compressor is disconnected, inverter check mode starts.” No row of the indoor lamp table 9-4 uses 9 blinks. | GL, FS, FH, GS06–24, GS30/36 | Technician | GL outdoor service p. 47; FS outdoor service p. 31; FH outdoor service p. 35; GS outdoor service p. 65 |
| P1 | “Intake sensor error” Self-check with a wireless remote: 1 beep and blink (output pattern A, detected by the indoor unit). Action table: room temperature thermistor (TH1), short at 194°F (90°C) or more, open at −40°F (−40°C) or less. | PKA-A KA8, PKA-A LA1, PLA-A EA8 | Technician | TCH115A (PKA-A KA8) p. 12; TCH115A (PKA-A KA8) p. 14; TCH117 (PKA-A LA1) p. 12; TCH117 (PKA-A LA1) p. 14; TCH120A (PLA-A EA8) p. 16; TCH120A (PLA-A EA8) p. 18 |
| P2 | “Pipe (TH2) sensor error” Self-check: 2 beeps and blinks, shared with P9. Action table: liquid pipe temperature thermistor (TH2). | PKA-A KA8, PKA-A LA1, PLA-A EA8 | Technician | TCH115A (PKA-A KA8) p. 12; TCH115A (PKA-A KA8) p. 14; TCH117 (PKA-A LA1) p. 12; TCH117 (PKA-A LA1) p. 14; TCH120A (PLA-A EA8) p. 16; TCH120A (PLA-A EA8) p. 18 |
| P9 | “Pipe (TH5) sensor error” Self-check: 2 beeps and blinks, shared with P2. Action table: condenser/evaporator temperature thermistor (TH5). | PKA-A KA8, PKA-A LA1, PLA-A EA8 | Technician | TCH115A (PKA-A KA8) p. 12; TCH115A (PKA-A KA8) p. 16; TCH117 (PKA-A LA1) p. 12; TCH117 (PKA-A LA1) p. 16; TCH120A (PLA-A EA8) p. 16; TCH120A (PLA-A EA8) p. 20 |
| E6 | “Indoor/outdoor unit communication error” What to check Self-check: 3 beeps and blinks, shared with E7. Action table: signal receiving error; the indoor controller board cannot receive any signal normally for 6 minutes after power-on, or for 3 minutes. | PKA-A KA8, PKA-A LA1, PLA-A EA8 | Technician | TCH115A (PKA-A KA8) p. 12; TCH115A (PKA-A KA8) p. 17; TCH117 (PKA-A LA1) p. 12; TCH117 (PKA-A LA1) p. 17; TCH120A (PLA-A EA8) p. 16; TCH120A (PLA-A EA8) p. 22 |
| E7 | “Indoor/outdoor unit communication error” Self-check: 3 beeps and blinks, shared with E6. Action table: transmitting error; “1” is received 30 times in a row although the indoor controller board sent “0”. | PKA-A KA8, PKA-A LA1, PLA-A EA8 | Technician | TCH115A (PKA-A KA8) p. 12; TCH115A (PKA-A KA8) p. 17; TCH117 (PKA-A LA1) p. 12; TCH117 (PKA-A LA1) p. 17; TCH120A (PLA-A EA8) p. 16; TCH120A (PLA-A EA8) p. 22 |
| P4 | “Drain sensor error/Float switch connector (CN4F) open” Self-check: 4 beeps and blinks. Action table: contact failure of the drain float switch connector CN4F. | PKA-A KA8, PKA-A LA1, PLA-A EA8 | Technician | TCH115A (PKA-A KA8) p. 12; TCH115A (PKA-A KA8) p. 14; TCH117 (PKA-A LA1) p. 12; TCH117 (PKA-A LA1) p. 14; TCH120A (PLA-A EA8) p. 16; TCH120A (PLA-A EA8) p. 18 |
| P5 | “Drain pump error” What to check Self-check: 5 beeps and blinks, shared with PA. Action table: drain overflow protection; the float switch detected underwater for 1 minute 30 seconds with the drain pump on turns off the compressor and the indoor fan. The PLA-A EA8 manual adds drain pump lock protection (PLA-A EA8 Service Manual TCH120A, p. 19). | PKA-A KA8, PKA-A LA1, PLA-A EA8 | Technician | TCH115A (PKA-A KA8) p. 12; TCH115A (PKA-A KA8) p. 14; TCH117 (PKA-A LA1) p. 12; TCH117 (PKA-A LA1) p. 14; TCH120A (PLA-A EA8) p. 16; TCH120A (PLA-A EA8) p. 19 |
| PA | “Forced compressor stop(due to water leakage abnormality)” Self-check: 5 beeps and blinks, shared with P5. Action table: once detected, the water leakage abnormality is not released until the main power is reset. | PKA-A KA8, PKA-A LA1, PLA-A EA8 | Technician | TCH115A (PKA-A KA8) p. 12; TCH115A (PKA-A KA8) p. 16; TCH117 (PKA-A LA1) p. 12; TCH117 (PKA-A LA1) p. 18; TCH120A (PLA-A EA8) p. 16; TCH120A (PLA-A EA8) p. 21 |
| P6 | “Freezing/Overheating protection operation” What to check Self-check: 6 beeps and blinks. Action table: the pipe temperature stays below −5°F (−15°C) in cooling or rises above 158°F (70°C) in heating, and does so again after a 6-minute resume prevention period. | PKA-A KA8, PKA-A LA1, PLA-A EA8 | Technician | TCH115A (PKA-A KA8) p. 12; TCH115A (PKA-A KA8) p. 15; TCH117 (PKA-A LA1) p. 12; TCH117 (PKA-A LA1) p. 15; TCH120A (PLA-A EA8) p. 16; TCH120A (PLA-A EA8) p. 19 |
| EE | “Combination error between indoor and outdoor units” Self-check: 7 beeps and blinks. The self-diagnosis action tables in these manuals have no row for EE. | PKA-A KA8, PKA-A LA1, PLA-A EA8 | Technician | TCH115A (PKA-A KA8) p. 12; TCH117 (PKA-A LA1) p. 12; TCH120A (PLA-A EA8) p. 16 |
| P8 | “Pipe temperature error” What to check Self-check: 8 beeps and blinks. Action table: the pipe temperature is out of the cooling or heating range; detection takes at least 9 minutes in cooling and 27 minutes in heating, and P8 is not detected in drying mode. | PKA-A KA8, PKA-A LA1, PLA-A EA8 | Technician | TCH115A (PKA-A KA8) p. 12; TCH115A (PKA-A KA8) p. 15; TCH117 (PKA-A LA1) p. 12; TCH117 (PKA-A LA1) p. 15; TCH120A (PLA-A EA8) p. 16; TCH120A (PLA-A EA8) p. 20 |
| E4 | “Remote controller signal receiving error” Self-check: 9 beeps and blinks, shared with E5. Action table, in one row with E0: the indoor controller board cannot receive data normally from the remote controller board or another indoor controller board for 3 minutes, or any signal from the remote controller for 2 minutes. | PKA-A KA8, PKA-A LA1, PLA-A EA8 | Technician | TCH115A (PKA-A KA8) p. 12; TCH115A (PKA-A KA8) p. 16; TCH117 (PKA-A LA1) p. 12; TCH117 (PKA-A LA1) p. 16; TCH120A (PLA-A EA8) p. 16; TCH120A (PLA-A EA8) p. 21 |
| E5 | “Remote controller signal receiving error” Self-check: 9 beeps and blinks, shared with E4. Action table, in one row with E3: the indoor controller board could not find a blank in the transmission path, or its sent and received data differed 30 times in a row. | PKA-A KA8, PKA-A LA1, PLA-A EA8 | Technician | TCH115A (PKA-A KA8) p. 12; TCH115A (PKA-A KA8) p. 17; TCH117 (PKA-A LA1) p. 12; TCH117 (PKA-A LA1) p. 17; TCH120A (PLA-A EA8) p. 16; TCH120A (PLA-A EA8) p. 21 |
| Pb | “Indoor unit fan motor error” Self-check: 11 beeps and blinks. Action table: fan motor trouble; the causes listed are a defective fan motor or indoor controller board, or a contact failure of the fan motor connector. | PKA-A KA8, PKA-A LA1, PLA-A EA8 | Technician | TCH115A (PKA-A KA8) p. 12; TCH115A (PKA-A KA8) p. 16; TCH117 (PKA-A LA1) p. 12; TCH117 (PKA-A LA1) p. 18; TCH120A (PLA-A EA8) p. 16; TCH120A (PLA-A EA8) p. 22 |
| Fb | “Indoor unit control system error (memory error, etc.)” Self-check: 12 beeps and blinks. The manuals give FB in parentheses as the form for the PAR-41MAA controller. Action table: data cannot be read from the nonvolatile memory of the indoor controller board; replace the board. | PKA-A KA8, PKA-A LA1, PLA-A EA8 | Technician | TCH115A (PKA-A KA8) p. 12; TCH115A (PKA-A KA8) p. 17; TCH117 (PKA-A LA1) p. 12; TCH117 (PKA-A LA1) p. 17; TCH120A (PLA-A EA8) p. 16; TCH120A (PLA-A EA8) p. 22 |
| PL | “Abnormal refrigerant circuit” Self-check: 14 beeps and blinks. Action table: in cooling, drying or auto cooling, the compressor has run 30 seconds or more and the liquid pipe or condenser/evaporator temperature is 167°F (75°C) or more; the error is not cancelled until the power source is reset. | PKA-A KA8, PKA-A LA1, PLA-A EA8 | Technician | TCH115A (PKA-A KA8) p. 12; TCH115A (PKA-A KA8) p. 17; TCH117 (PKA-A LA1) p. 12; TCH117 (PKA-A LA1) p. 16; TCH120A (PLA-A EA8) p. 16; TCH120A (PLA-A EA8) p. 22 |
| E0 | “Remote controller transmission error” No sound in wireless self-check; shown on a wired controller. Action table: a main or sub remote controller receives no normal transmission from the indoor unit of refrigerant address “0” for 3 minutes, or a sub remote controller receives no signal for 2 minutes. | PKA-A KA8, PKA-A LA1, PLA-A EA8 | Technician | TCH115A (PKA-A KA8) p. 12; TCH115A (PKA-A KA8) p. 16; TCH117 (PKA-A LA1) p. 12; TCH117 (PKA-A LA1) p. 16; TCH120A (PLA-A EA8) p. 16; TCH120A (PLA-A EA8) p. 21 |
| E3 | “Remote controller transmission error” No sound in wireless self-check. Action table: the remote controller could not find a blank in the transmission path for 6 seconds, or its sent and received data differed 30 times in a row. | PKA-A KA8, PKA-A LA1, PLA-A EA8 | Technician | TCH115A (PKA-A KA8) p. 12; TCH115A (PKA-A KA8) p. 17; TCH117 (PKA-A LA1) p. 12; TCH117 (PKA-A LA1) p. 17; TCH120A (PLA-A EA8) p. 16; TCH120A (PLA-A EA8) p. 21 |
| E1 | “Remote controller control board error” No sound in wireless self-check. Action table: data cannot be read from the nonvolatile memory of the remote controller control board; replace the remote controller. | PKA-A KA8, PKA-A LA1, PLA-A EA8 | Technician | TCH115A (PKA-A KA8) p. 12; TCH115A (PKA-A KA8) p. 17; TCH117 (PKA-A LA1) p. 12; TCH117 (PKA-A LA1) p. 17; TCH120A (PLA-A EA8) p. 16; TCH120A (PLA-A EA8) p. 22 |
| E2 | “Remote controller control board error” No sound in wireless self-check. Action table: the remote controller's clock function does not work normally; replace the remote controller. | PKA-A KA8, PKA-A LA1, PLA-A EA8 | Technician | TCH115A (PKA-A KA8) p. 12; TCH115A (PKA-A KA8) p. 17; TCH117 (PKA-A LA1) p. 12; TCH117 (PKA-A LA1) p. 17; TCH120A (PLA-A EA8) p. 16; TCH120A (PLA-A EA8) p. 22 |
| E9 | “Indoor/outdoor unit communication error (Transmitting error) (Outdoor unit)” Self-check output pattern B (detected by a unit other than the indoor unit): the lamp stays on for about 3 seconds, then 1 blink. The self-diagnosis action table does not cover codes detected in the outdoor unit and refers to the outdoor unit's service manual, which is not among our sources (PKA-A24/30/36KA8 Service Manual TCH115A, p. 14). | PKA-A KA8, PKA-A LA1, PLA-A EA8 | Technician | TCH115A (PKA-A KA8) p. 12; TCH117 (PKA-A LA1) p. 12; TCH120A (PLA-A EA8) p. 16 |
| UP | “Compressor overcurrent interruption” Self-check output pattern B, 2 beeps and blinks. Detected by the outdoor unit; these manuals give only this line and refer to the outdoor unit's service manual. | PKA-A KA8, PKA-A LA1, PLA-A EA8 | Technician | TCH115A (PKA-A KA8) p. 12; TCH117 (PKA-A LA1) p. 12; TCH120A (PLA-A EA8) p. 16 |
| U3, U4 | “Open/short of outdoor unit thermistors” Self-check output pattern B, 3 beeps and blinks. Detected by the outdoor unit; these manuals give only this line and refer to the outdoor unit's service manual. | PKA-A KA8, PKA-A LA1, PLA-A EA8 | Technician | TCH115A (PKA-A KA8) p. 12; TCH117 (PKA-A LA1) p. 12; TCH120A (PLA-A EA8) p. 16 |
| UF | “Compressor overcurrent interruption (When compressor locked)” Self-check output pattern B, 4 beeps and blinks. Detected by the outdoor unit; these manuals give only this line and refer to the outdoor unit's service manual. | PKA-A KA8, PKA-A LA1, PLA-A EA8 | Technician | TCH115A (PKA-A KA8) p. 12; TCH117 (PKA-A LA1) p. 12; TCH120A (PLA-A EA8) p. 16 |
| U2 | “Abnormal high discharge temperature/49C operated/insufficient refrigerant” Self-check output pattern B, 5 beeps and blinks. Detected by the outdoor unit; these manuals give only this line and refer to the outdoor unit's service manual. | PKA-A KA8, PKA-A LA1, PLA-A EA8 | Technician | TCH115A (PKA-A KA8) p. 12; TCH117 (PKA-A LA1) p. 12; TCH120A (PLA-A EA8) p. 16 |
| U1, Ud | “Abnormal high pressure (63H operated)/Overheating protection operation” Self-check output pattern B, 6 beeps and blinks. Ud is printed with UD in parentheses, the form the manuals give for the PAR-41MAA controller. Detected by the outdoor unit; these manuals give only this line and refer to the outdoor unit's service manual. | PKA-A KA8, PKA-A LA1, PLA-A EA8 | Technician | TCH115A (PKA-A KA8) p. 12; TCH117 (PKA-A LA1) p. 12; TCH120A (PLA-A EA8) p. 16 |
| U5 | “Abnormal temperature of heat sink” Self-check output pattern B, 7 beeps and blinks. Detected by the outdoor unit; these manuals give only this line and refer to the outdoor unit's service manual. | PKA-A KA8, PKA-A LA1, PLA-A EA8 | Technician | TCH115A (PKA-A KA8) p. 12; TCH117 (PKA-A LA1) p. 12; TCH120A (PLA-A EA8) p. 16 |
| U8 | “Outdoor unit fan protection stop” Self-check output pattern B, 8 beeps and blinks. Detected by the outdoor unit; these manuals give only this line and refer to the outdoor unit's service manual. | PKA-A KA8, PKA-A LA1, PLA-A EA8 | Technician | TCH115A (PKA-A KA8) p. 12; TCH117 (PKA-A LA1) p. 12; TCH120A (PLA-A EA8) p. 16 |
| U6 | “Compressor overcurrent interruption/Abnormal of power module” Self-check output pattern B, 9 beeps and blinks. Detected by the outdoor unit; these manuals give only this line and refer to the outdoor unit's service manual. | PKA-A KA8, PKA-A LA1, PLA-A EA8 | Technician | TCH115A (PKA-A KA8) p. 12; TCH117 (PKA-A LA1) p. 12; TCH120A (PLA-A EA8) p. 16 |
| U7 | “Abnormality of super heat due to low discharge temperature” Self-check output pattern B, 10 beeps and blinks. Detected by the outdoor unit; these manuals give only this line and refer to the outdoor unit's service manual. | PKA-A KA8, PKA-A LA1, PLA-A EA8 | Technician | TCH115A (PKA-A KA8) p. 12; TCH117 (PKA-A LA1) p. 12; TCH120A (PLA-A EA8) p. 16 |
| U9, UH | “Abnormality such as overvoltage or voltage shortage and abnormal synchronous signal to main circuit/Current sensor error” Self-check output pattern B, 11 beeps and blinks. Detected by the outdoor unit; these manuals give only this line and refer to the outdoor unit's service manual. | PKA-A KA8, PKA-A LA1, PLA-A EA8 | Technician | TCH115A (PKA-A KA8) p. 12; TCH117 (PKA-A LA1) p. 12; TCH120A (PLA-A EA8) p. 16 |
How to read a Mitsubishi blink code
MSZ and MSY wall units of the GL, FS, FH and GS series show a fault as blinks of the OPERATION INDICATOR lamp on the indoor unit: a count of blinks, a 2.5-second pause, then the count again. A steady blink, 0.5 second on and 0.5 second off, is a code of its own MSZ-GL Indoor Service Manual OBH732D, p. 27. The blinking lamp is the upper one on GL and GS06–24 and the left one on FS, FH and GS30/36 MSZ-FS Indoor Service Manual OBH872A, p. 24; MSZ-GS Indoor Service Manual OBH874A, pp. 38–39.
The outdoor unit has a separate LED on its inverter P.C. board. It stays lit in normal operation and blinks a count after each 2.5-second pause, with meanings of its own MUZ-GL Outdoor Service Manual OBH733J, p. 46. The owner’s manuals say the user should not disassemble, alter or repair the unit MSZ-GL Operating Instructions, p. En-1, so that LED is read by a technician. So is failure mode recall, where the remote calls up the last stored fault and the same counts mean other things MSZ-GL Indoor Service Manual OBH732D, pp. 24–25.
P-Series PKA-A and PLA-A indoor units show two-character check codes such as E6 or P8 on a wired controller, and the same code as beeps and blinks in self-check with a wireless remote PKA-A24/30/36KA8 Service Manual TCH115A, p. 12. The M-Series manuals have no such table; the M-Series Controls book refers code contents to the indoor unit’s installation manual or service handbook M-Series Controls, December 2016, p. 46. The outdoor tables here come from the MUZ and MUY manuals, not from MXZ multi-zone units. The GL owner’s manual we use covers GL06 to GL15 only.
What the owner’s manuals explain
The troubleshooting tables in all seven owner’s manuals explain these symptoms: heating stops for up to 10 minutes while the outdoor unit defrosts, vapor from defrosting looks like white smoke, water drips from the outdoor unit, and the unit cannot be operated for about 3 minutes after a restart MSZ-GL Operating Instructions, p. En-11; MSZ-FS Operating Instructions, p. En-13; MSZ-FH Operating Instructions, p. En-12; MSZ-GS06/09/12/15 Operating Instructions, p. En-12; MSZ-GS18 Operating Instructions, p. En-13; MSZ-GS24 Operating Instructions, p. En-13; MSZ-GS30/36 Operating Instructions, p. En-13.
On a multi-zone system, the GL and FS lamp charts show standby as the upper or left lamp lit and the other lamp blinking MSZ-GL Operating Instructions, p. En-5; MSZ-FS Operating Instructions, p. En-6. The FS, FH and GS06–24 manuals exclude that standby blink from the stop-and-call list MSZ-FS Operating Instructions, p. En-13; MSZ-FH Operating Instructions, p. En-12; MSZ-GS06/09/12/15 Operating Instructions, p. En-13; MSZ-GS18 Operating Instructions, p. En-14; MSZ-GS24 Operating Instructions, p. En-14.
The lower outdoor limit for heating is −4°F (−20°C) for GL MSZ-GL Operating Instructions, p. En-12 and −13°F (−25°C) for FS and FH MSZ-FS Operating Instructions, p. En-14; MSZ-FH Operating Instructions, p. En-13. On GS06–24 it is −4°F with MUZ-GS NA or NAH and MUY-GS outdoor units and −13°F with MUZ-GS NAHZ MSZ-GS06/09/12/15 Operating Instructions, p. En-14; MSZ-GS18 Operating Instructions, p. En-15; MSZ-GS24 Operating Instructions, p. En-15. These manuals add that below the limit the outdoor unit may stop until it gets warmer. GS30/36 prints −4°F (−20°C) without that note MSZ-GS30/36 Operating Instructions, p. En-15.
Clearing a code
The owner’s manuals give no reset for a blink code, and they warn not to switch the breaker on or off while the unit runs, because of sparks and fire MSZ-GL Operating Instructions, p. En-1. A technician deletes the stored fault in recall mode after the repair MSZ-GL Indoor Service Manual OBH732D, p. 24. A PAR-40MAAU wired controller resets a displayed error with F4 or ON/OFF, after telling you to stop the operation and consult your dealer PAR-40MAAU Instruction Book, pp. 65–66.
When to stop and call a professional
Stop using the unit and consult your dealer when the lamp blinks, water leaks or drips from the indoor unit, the breaker trips often, you hear an abnormal sound or you find a refrigerant leak MSZ-GL Operating Instructions, p. En-11. With a burning smell, stop it, turn the breaker off or unplug it, and consult your dealer. If it does not cool or heat, refrigerant may be leaking MSZ-GL Operating Instructions, p. En-1. Refrigerant work is for a technician certified under EPA Section 608.
See also
Mitsubishi Electric is a trademark of its owner. How House Works is not affiliated with or endorsed by Mitsubishi Electric.
Sources
- Mitsubishi Electric Corporation. MSZ-GL Indoor Service Manual OBH732D. No. OBH732, Revised Edition-D, issued Feb. 2022; covers MSZ-GL06–24NA and MSY-GL09–24NA. Accessed Oct 12, 2026.
- Mitsubishi Electric Corporation. MUZ-GL Outdoor Service Manual OBH733J. No. OBH733, Revised Edition-J, issued Jun. 2021; covers MUZ-GL09–24NA and NAH, MUY-GL09–24NA (the cover lists no MUZ-GL06). Copy hosted by a Mitsubishi distributor (Gemaire/Baker Distributing).. Accessed Oct 12, 2026.
- Mitsubishi Electric Corporation. MSZ-FS Indoor Service Manual OBH872A. No. OBH872, Revised Edition-A, issued Nov. 2021. Accessed Oct 12, 2026.
- Mitsubishi Electric Corporation. MUZ-FS Outdoor Service Manual OBH873B. No. OBH873, Revised Edition-B, issued Aug. 2021; covers MUZ-FS06–18NA and NAH. Accessed Oct 12, 2026.
- Mitsubishi Electric Corporation. MSZ-FH Indoor Service Manual OBH683E. No. OBH683, Revised Edition-E, issued Nov. 2021. Copy hosted by a Mitsubishi distributor (Gemaire).. Accessed Oct 12, 2026.
- Mitsubishi Electric Corporation. MUZ-FH Outdoor Service Manual OBH684E. No. OBH684, Revised Edition-E, issued Jun. 2021; covers MUZ-FH06–18NA and NAH. Copy hosted by a Mitsubishi distributor (Gemaire).. Accessed Oct 12, 2026.
- Mitsubishi Electric Corporation. MSZ-GS Indoor Service Manual OBH874A. No. OBH874, Revised Edition-A, issued Oct. 2022; covers MSZ-GS06–36 and MSY-GS09–36; table 9-4 is on p. 38 for GS06–24 and p. 39 for GS30/36. Copy hosted by a Mitsubishi distributor (Meier Supply).. Accessed Oct 12, 2026.
- Mitsubishi Electric Corporation. MUZ-GS Outdoor Service Manual OBH875B. No. OBH875, Revised Edition-B, issued Oct. 2022; covers MUZ-GS NA, NAH and NAHZ, MUY-GS NA, and the GS30/36 NA2 and NAH2 outdoor units. Copy hosted by a Mitsubishi distributor (Meier Supply).. Accessed Oct 12, 2026.
- Mitsubishi Electric. MSZ-GL Operating Instructions. Printed code DG79A01LH01 (the file name says JG79Y190H02); no publication date printed; covers MSZ-GL06/09/12/15NA and MSY-GL09/12/15NA; English pages are numbered En-1 onward. Accessed Oct 12, 2026.
- Mitsubishi Electric. MSZ-FS Operating Instructions. Printed code JG79Y766H01; no publication date printed; covers MSZ-FS06/09/12/15/18NA; English pages are numbered En-1 onward. Accessed Oct 12, 2026.
- Mitsubishi Electric. MSZ-FH Operating Instructions. Printed code JG79A806H05, layout date 2019/06/27; a newer revision may exist on Mitsubishi's MyLinkDrive portal (not checked); covers MSZ-FH06/09/12/15/18NA and MSZ-FH18NA2; English pages are numbered En-1 onward. Copy hosted by a Mitsubishi distributor (Meier Supply).. Accessed Oct 12, 2026.
- Mitsubishi Electric. MSZ-GS06/09/12/15 Operating Instructions. Printed code DG79A04SH01; no publication date printed; covers MSZ-GS06/09/12/15NA and MSY-GS09/12/15NA; English pages are numbered En-1 onward. Copy hosted by a Mitsubishi distributor (Meier Supply).. Accessed Oct 12, 2026.
- Mitsubishi Electric. MSZ-GS18 Operating Instructions. Printed code DG79A05BH01; no publication date printed; covers MSZ-GS18NA and MSY-GS18NA; English pages are numbered En-1 onward. Accessed Oct 12, 2026.
- Mitsubishi Electric. MSZ-GS24 Operating Instructions. Printed code DG79A05EH01; no publication date printed; covers MSZ-GS24NA and MSY-GS24NA; English pages are numbered En-1 onward. Copy hosted by a Mitsubishi distributor (Meier Supply).. Accessed Oct 12, 2026.
- Mitsubishi Electric. MSZ-GS30/36 Operating Instructions. Printed code DG79A00AH01; no publication date printed; covers MSZ-GS30NA2 and MSZ-GS36NA2 and the MSY versions; English pages are numbered En-1 onward. Accessed Oct 12, 2026.
- Mitsubishi Electric. MSZ-GL Installation Manual. Printed code JG79Y036H01; covers MSZ-GL06/09/12/15NA and MSY-GL09/12/15NA; no page numbers printed, page references are PDF pages. Accessed Oct 12, 2026.
- Mitsubishi Electric. MSZ-FS Installation Manual. Printed code JG79J820H01; covers MSZ-FS06/09/12/15/18NA; no page numbers printed, page references are PDF pages. Accessed Oct 12, 2026.
- Mitsubishi Electric. MSZ-FH Installation Manual. Printed code JG79A805H05 (the file name says JG79A805H03); covers MSZ-FH09/12/15/18NA; no page numbers printed, page references are PDF pages. Accessed Oct 12, 2026.
- Mitsubishi Electric. MSZ-GS Installation Manual. Printed code JG79N458H03 (the file name says JG79N458H01); covers MSZ-GS06–24NA and MSY-GS09–24NA; no page numbers printed, page references are PDF pages. Accessed Oct 12, 2026.
- Mitsubishi Electric. M-Series Controls, December 2016. December 2016; controls data for M-Series units, filed as the PAC-US444CN-1 manual. Accessed Oct 12, 2026.
- Mitsubishi Electric. PAR-40MAAU Instruction Book. Printed code WT09033X01; MA remote controller for CITY MULTI, M-series and P-series air conditioners. Accessed Oct 12, 2026.
- Mitsubishi Electric Corporation. PKA-A24/30/36KA8 Service Manual TCH115A. No. TCH115, Revised Edition-A, August 2023. Accessed Oct 12, 2026.
- Mitsubishi Electric Corporation. PKA-A12/18LA1 Service Manual TCH117. No. TCH117, March 2023. Accessed Oct 12, 2026.
- Mitsubishi Electric Corporation. PLA-A EA8 Service Manual TCH120A. No. TCH120, Revised Edition-A, August 2023; covers PLA-A12/18/24/30/36/42/48EA8. Accessed Oct 12, 2026.