Samsung AC error codes – Inverter split AR09/12/18/24HSF
39 codes from the Samsung service manual, with what each one means and the usual causes. Indoor shows the code on the 7-segment display. Outdoor PBA has 3 LEDs: YEL, GRN, RED (on / off / blinking). Normal outdoor display: RED on, GRN blinking, YEL off.
You can safely switch the unit off at the switch, wait 5 minutes and switch on again. Don't open the unit, touch wiring or handle gas: these checks need a trained technician.
E101also E102
Communication error between indoor and outdoor unit
Usual causes
- Indoor-outdoor connecting cable loose, wrong or cut
- Power cable and communication cable crossed
- Indoor or outdoor PBA has no power
- Indoor PBA or outdoor PBA faulty
What our technician checks
- Switch off, wait, restart - see if the error returns
- Check all 5 connecting wires are on matching terminals indoor and outdoor
- Check power reaches both units (indoor lamp / outdoor LEDs)
E121
Indoor room temperature sensor error
Usual causes
- Sensor connector loose
- Sensor open/short (resistance out of range)
- Indoor PBA faulty
What our technician checks
- Unplug sensor from PBA and measure: 10 kΩ ±3% at 25°C (20°C 12.09k, 30°C 8.31k, 35°C 6.94k, 40°C 5.83k)
- Refit sensor, power on and measure voltage at connector pins #1-#2: below 0.5 V or above 4.5 V means PBA problem
E122also E123
Indoor coil sensor error (Eva-MID / Eva-IN pipe sensor)
Usual causes
- Sensor connector loose or sensor out of its pipe holder
- Sensor open/short
- Indoor PBA faulty
What our technician checks
- Measure sensor pins #3-#4 and #5-#6: 10 kΩ ±3% at 25°C (20°C 12.09k, 30°C 8.31k)
- Power on: pin voltage below 0.5 V or above 4.5 V = PBA fault
E154
Indoor BLDC fan motor error (speed feedback missing)
Usual causes
- Fan motor connector CN72 loose
- Fan motor shorted / seized
- Indoor PBA fan drive faulty
- Supply voltage wrong
What our technician checks
- Power off, unplug CN72, check for short between pins #1-#6 of the motor
- Power on: CN72 #1-#3 should be over 250 V DC
- During operation CN72 #3-#5 and #3-#6 should be 1-15 V DC
E162
Indoor EEPROM error
Usual causes
- Indoor PBA EEPROM corrupted
What our technician checks
- Power reset
E163
Option code error (indoor option not set / wrong)
Usual causes
- Wrong option code after PBA change
What our technician checks
- Check option code matches the model
E203
Communication time-out between inverter micom and main micom (outdoor PBA)
Usual causes
- Outdoor PBA internal fault
- Power noise
What our technician checks
- Power reset
E221
Outdoor (ambient) temperature sensor error
Usual causes
- Connector CN251 loose or wrong position
- Sensor open/short
- Outdoor PBA faulty
What our technician checks
- Check CN251 fitted correctly (by colour)
- Measure CN251 #1-#2: 10 kΩ ±3% at 25°C
- Power on: voltage below 0.5 V or above 4.5 V = PBA fault
E231
Outdoor condenser (coil) temperature sensor error
Usual causes
- CN251 loose
- Sensor open/short
- Outdoor PBA faulty
What our technician checks
- Measure CN251 #5-#6: 10 kΩ ±3% at 25°C
- Power on: below 0.5 V or above 4.5 V = PBA fault
E251
Discharge temperature sensor error
Usual causes
- CN251 loose
- Sensor open/short
- Outdoor PBA faulty
What our technician checks
- Measure CN251 #3-#4: 200 kΩ ±3% at 25°C (20°C 242k, 30°C 166k, 35°C 138k, 40°C 115k)
- Power on: below 0.5 V or above 4.5 V = PBA fault
E416
Discharge over-temperature (compressor running too hot)
Usual causes
- Gas shortage / leak
- Compressor locking
- Very high outdoor temperature or blocked airflow
- EEPROM data wrong
- Outdoor PBA fault
What our technician checks
- Wait 30 min-1 hr, restart
- Check gas pressure and leaks
- Check condenser clean and fan running
E422
EEV or service valve closed (self-diagnosis)
Usual causes
- Service valve not fully open
- EEV coil unplugged (CN701) or EEV stuck
- Gas leak / low charge
- Indoor Eva-in sensor out of position
What our technician checks
- Check indoor Eva-in sensor position
- Restart after 20 min
- Listen for EEV clicking at power on, check CN701
- Check refrigerant pressure
E440
Operation stopped - outdoor temperature out of range (heating)
Usual causes
- Outdoor temperature over 40°C or under -30°C in heat mode
What our technician checks
- Check temperature around outdoor unit
E441
Operation stopped - outdoor temperature out of range (cooling)
Usual causes
- Outdoor temperature under -7°C in cool mode
What our technician checks
- Check temperature around outdoor unit
E458
Outdoor BLDC fan motor error
Usual causes
- Motor connector CN901 loose
- Obstruction at the propeller
- Motor shorted
- Outdoor PBA fan drive faulty
What our technician checks
- Check nothing blocks the fan
- Unplug CN901: short between pins #1-#6 = motor bad
- CN901 #1-#3 over 250 V DC
- Running: #3-#5 and #3-#6 between 1-15 V DC
E461
Compressor starting error
Usual causes
- Compressor wires loose or wrong order
- Compressor winding / insulation fault
- EEPROM data wrong
- Outdoor PBA (IPM) fault
What our technician checks
- Compressor wire order U-RED, V-BLUE, W-YELLOW
- Measure U-V, V-W, W-U resistance (should be equal) and insulation to body
E462
AC input current limit trip (PFC over current)
Usual causes
- Overload - very hot outdoor, dirty coils
- Temperature sensor out of place giving wrong reading
- PFC shunt resistor open (R410-R412 / R408-R410)
- Compressor cable / power terminal loose
What our technician checks
- Check site load conditions
- Check sensor positions and values
- Check compressor and power terminal connections
E464
IPM over current (O.C) error
Usual causes
- IPM shunt resistor open
- Abnormal overload condition
- Sensor detached or wrong reading
- Compressor winding fault / wires loose
What our technician checks
- Check compressor wire connections
- Check site load (indoor/outdoor temperature)
- Check sensor position and values
- Check compressor winding resistance and insulation
E465
Compressor voltage / current limit error
Usual causes
- IPM shunt open
- Overload
- Sensor error
- Compressor winding fault
What our technician checks
- Same as E464: wiring, load, sensors, compressor resistance/insulation
E466
DC-link voltage under / over
Usual causes
- Supply voltage outside 180-270 V AC
- Reactor wire loose
- DC-link capacitor or sensing resistor fault on outdoor PBA
What our technician checks
- Input voltage at power cord 180-270 V AC
- DC-link voltage in operation 280-320 V DC
- DC-link sensing voltage 0.2-4.0 V DC
- Reactor insulation
E467
Compressor wire missing / rotation error
Usual causes
- Compressor lead disconnected or wrong order
- Compressor winding fault
- Outdoor PBA fault
What our technician checks
- Check PBA-to-compressor wiring U-RED, V-BLUE, W-YELLOW
- Winding resistance and insulation
E468
Current sensor error
Usual causes
- PFC or IPM shunt resistor open
- Short/open around current sensing IC (IC451)
What our technician checks
- Check shunt resistor values
E469
DC-link voltage sensor error
Usual causes
- Abnormal input voltage
- Reactor wire loose
- DC-link capacitor / resistor fault
What our technician checks
- DC-link voltage in operation 280-320 V DC
- Sensing voltage 0.2-4.8 V DC
- Reactor insulation
E470
Outdoor EEPROM data error (no data)
Usual causes
- EEPROM not downloaded after PBA change
- Short around micom / EEPROM connector
What our technician checks
- Was a new PBA fitted without EEPROM data?
E471
EEPROM / OTP data error between main micom and inverter micom
Usual causes
- EEPROM data mismatch after PBA change
- Outdoor PBA fault
E472
AC zero-cross signal error
Usual causes
- Power noise at customer's house
- Recent power failure
- Outdoor PBA fault
What our technician checks
- Check supply quality
E474
Heatsink (IPM) temperature sensor error
Usual causes
- PBA-heatsink screws loose / gap
- Outdoor fan not running
- Control-box cover not fitted
What our technician checks
- Check the 4 heatsink screws
- Check outdoor fan running
E483
Over-voltage protection (hardware DC-link)
Usual causes
- Input voltage too high (above 270 V AC
- 300 V AC is damaging)
- Reactor / DC-link circuit fault
What our technician checks
- Measure supply voltage
- DC-link 280-320 V DC in operation
E484
PFC over load
Usual causes
- Low/high supply voltage
- Reactor wire loose
- PFC resistor fault
What our technician checks
- Same as E466
E485
Input current sensor error
Usual causes
- PFC / IPM shunt open
- Current sensing circuit fault
What our technician checks
- Check shunt resistors
E488
AC input voltage sensor error
Usual causes
- Abnormal input voltage
- Reactor wire loose
- PFC resistor (R105-R108) fault
What our technician checks
- DC-link sensing voltage 0.2-4.8 V DC in operation
- Reactor insulation
E500
Heatsink over-temperature
Usual causes
- Heatsink screws loose, poor contact
- Outdoor fan not running / blocked airflow
- Very hot site
What our technician checks
- Check heatsink screws
- Check outdoor fan and airflow
E554
Gas leak error
Usual causes
- Low refrigerant / leak
- Indoor Eva-in sensor out of position
- EEV not working or unplugged (CN701)
- Pipe crack
What our technician checks
- Check Eva-in sensor position
- Restart after 20 min
- Check EEV connection and listen for it at power on
- Check gas pressure, find leak
E556
Capacity mismatch between indoor and outdoor unit
Usual causes
- Indoor and outdoor units of different capacity
- Wrong indoor option code
- Wrong outdoor EEPROM data
What our technician checks
- Check BTU of both units match
No power (outdoor)
Outdoor unit dead - no LEDs (not displayed)
Usual causes
- Supply missing
- L/N/E or communication wire wrongly connected
- Fuse F001 open
- SMPS PBA fault
What our technician checks
- Terminal block L-N 200-240 V AC
- Fuse F001
- SMPS outputs: 15 V (14-15), 12 V (11-13), 5 V (4.5-5.5)
- DC-link capacitor 280-320 V DC after 3 min
Louver not moving
Up/down, left/right or grille louver motor not working (not displayed)
Usual causes
- Louver motor connector loose (CN61-CN63)
- Louver motor faulty
- PBA output faulty
What our technician checks
- Unplug 30 s and retry swing
- Check voltage changes on pins #2-#5 of CN61/62/63 when swing pressed
Remote not working
Indoor unit not receiving remote signal
Usual causes
- Display PBA connector loose
- Weak remote batteries
- Interference from electronic / CFL lights
What our technician checks
- Check connector and batteries
- Switch off room lights and test
Indoor dead
Indoor unit has no power / lamp off
Usual causes
- Fuse open
- Indoor fan motor short
- Power circuit / switching transformer fault
- Terminal block thermal fuse opened (loose indoor-outdoor connection caused heating)
What our technician checks
- Check 1st and 2nd fuse on indoor PCB
- Bridge (BD71) input 200-240 V AC
- 12 V and 5 V on PCB
- Check terminal block thermal fuse
Wi-Fi LED
Wi-Fi kit status LED: ON = connected; blink 0.5 s = router OK but no internet; blink 3 s = not connected to router; OFF = kit not connected to AC
Usual causes
- Internet down
- Router off / wrong setup
- Kit not connected to indoor unit
What our technician checks
- Check router and internet
- Check kit cable
Code not here, or still showing?
Send a photo of the display and the model sticker on WhatsApp. We'll tell you what it means and whether it needs a visit.
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