（1）Turn off the unit and wait for it to automatically recover.

（2）If ineffective, prioritize replacing the outdoor unit main control board or the entire outdoor unit.

（1）With the power disconnected, remove the protective cover of the outdoor unit fan blade. Visually inspect for foreign objects or mechanical jamming. Manually rotate the fan blades to check if they turn smoothly (please ensure the entire air conditioning system is powered off for safety), and check if the bearings are dry or damaged.

（2）With the power disconnected, trace the outdoor unit fan motor cable to locate the connector. Check the connection between the fan motor plug and the outdoor unit main control board for looseness, poor contact, or damage. Additionally, verify that the wire sequence is correct. If the newly installed outdoor fan rotates in reverse, first check if the colors of the three wires are correct. For connectors with anti-misinsertion design (after the locking plug is connected to the main board), the correct wire sequence should be Yellow (W), Red (V), Blue (U).（Note: The wiring sequence of the outdoor fan connector depends on the component）

（3）If all the above are normal, prioritize replacing the outdoor unit fan motor. If the E2 error code persists after replacement, replace the outdoor unit main control board or the entire outdoor unit.

（1）Power grid voltage inspection: Check if the user's power supply voltage is stable, too low, or too high.

（2）Check if the power supply to the outdoor unit main control board is normal, stable, and sufficient; verify that the voltage is not incorrectly connected (e.g., a 115V model mistakenly connected to 230V, or a 230V model connected to 115V).

（3）Voltage check: With power on, use a multimeter to measure the voltage across the terminals of the indoor unit to ensure it falls within the voltage range specified on the nameplate (typically within ±10% of the rated Voltage).

（4）Check that there are no obstructions blocking the air outlets of the indoor/outdoor units; inspect if the filter, evaporator, or condenser is dirty or clogged with dust.

（5）Check if the outdoor unit's three-way stop valve and two-way stop valve were left closed or partially open after vacuum pumping during installation, which could restrict refrigerant flow and cause false system detection. If the valves are closed, with the power off, remove the valve caps and turn the valve stems counterclockwise using an Allen wrench.

（6）Check for reversed connections, looseness, damage, or poor contact in the neutral and ground wiring.

（7）If E3 appears immediately on the indoor unit display right after startup, it generally indicates a hardware fault unrelated to voltage or system pressure. First, visually inspect the outdoor unit main control board for burnt components. With the power off, remove the cover from the top of the compressor and use a multimeter to measure the resistance between each pair of the three terminals on top of the compressor (in Ohms, the values should be approximately equal).

（8）Check if the three-phase AC wires—U (Black), V (White), and W (Orange)—are correctly connected to the corresponding terminals on both the outdoor unit main control board and the top of the compressor (refer to the letter markings on the indoor unit main control board and the top of the compressor).

（9）During system operation, listen for abnormal noises from the outdoor compressor. Verify if the vacuum pumping procedure was performed during installation; the system should have been evacuated for at least 15 minutes until the pressure reached -14.7 psig (-0.1 MPa).

（10）If all the above are normal, prioritize replacing the outdoor unit main control board.

（11）If the compressor only produces a buzzing electromagnetic sound without rotating when running, or if it runs for a while and then produces irregular sounds before reporting error code E3, it is highly likely that the compressor has seized or suffered mechanical damage, requiring replacement of the entire outdoor unit.

（1）The rotor of an air conditioner compressor is like the "piston" or "crankshaft" in a car engine; it serves as the core power component that drives the refrigerant to circulate within the AC system.

（2）Startup Failure: The compressor fails to start normally.

Running Out of Step: Inaccurate detection of the compressor rotor position leads to abnormal current or the motor losing synchronization.

（1）With the power off, inspect the wiring connections under the outdoor unit compressor cover for any signs of disconnection, poor contact, or damage.

（2）Check the wiring between the compressor plug and the outdoor main control board for disconnection, poor contact, or damage.

（3）Verify that the wiring sequence of the compressor plug matches the correct terminal sequence on the outdoor main control board (there may be letter markings).

（4）If all the above are normal, replace the components in the following order: Outdoor unit main control board → Outdoor unit.

(1) Phase Fault (General term for 3-phase power supply abnormalities):

Phase Loss: One phase of the three-phase AC power is disconnected (e.g., no voltage on L1, L2, or L3), preventing normal startup or causing overheating during operation.

Phase Sequence / Phase Rotation Error: The sequence of the three-phase power is reversed (e.g., connected as L1→L3→L2 instead of the required L1→L2→L3), also known as "Reverse Phase."

Voltage Imbalance: Excessive deviation in voltage between phases (e.g., L1-L2 = 460V, L2-L3 = 400V), which may damage motors.

(2) Hazards of Compressor Reversal:

Inability to establish refrigeration/heating cycle: Incorrect refrigerant flow direction.

Mechanical Damage: Valve plates, bearings, and rotors may be damaged due to abnormal stress.

Protective Shutdown: Modern inverter or intelligent main control boards detect abnormal startup (e.g., irregular current, failure to build pressure differential) and display errors such as "Phase Fault" or "Reverse".

（1）Determine whether the unit is newly installed or has been installed and used for a period based on the customer's order delivery time dimension (excluding cases where delivery occurs without installation).

（2）Check if the outdoor unit three-way stop valve and two-way stop valve were not opened, or if the opening degree is insufficient after vacuuming during installation, causing low refrigerant flow and system misjudgment. If the valves are closed, with the power disconnected, remove the valve stem caps and use an Allen wrench to turn counterclockwise to open them.

（3）Inspect the evaporator/condenser connecting pipes of the outdoor/indoor units for damage or cracks. Pay special attention to welding joints and pipe connections for oil stains (indicating refrigerant leakage). Apply soapy water to suspicious areas and observe for bubble formation.

（4）Check wiring continuity: Verify that the wiring between the indoor unit coil sensor and the indoor unit main control board is intact.

（5）Inspect the connection between the indoor unit coil sensor plug and the indoor unit main control board to ensure it is secure and not loose.

（6）Eliminate environmental factors: Check for possible causes such as water ingress, moisture, or high temperatures.

（7）After disconnecting the power, detach the indoor unit coil sensor from the main control board and use a multimeter to measure the resistance at the sensor terminals. The resistance should be approximately 20KΩ at 77℉. If the reading is approximately 0KΩ, it indicates a short circuit, and the sensor needs replacement. If the reading shows ∞ (infinite), it indicates an open circuit; inspect the wiring or the sensor.

（8）Check if the system pressure is too low: While operating in cooling mode, use a pressure gauge to check the pressure at the outdoor unit three-way stop valve (typical low pressure is around 0.8–1.0 Mpa (116.03–145.04 PSIG)). If the pressure is significantly lower than 0.8 Mpa (116.0 PSIG), the system is likely low on refrigerant.

（9）While the air conditioner is running, listen for abnormal compressor noise, which may indicate high pressure due to a lack of refrigerant.

（10）If all the above are normal, attempt to evacuate the system refrigerant, then perform vacuuming before recharging. If a vacuum cannot be achieved during evacuation, it indicates a leak in the system components. Recharge with R32 refrigerant according to the capacity specified on the outdoor unit nameplate.

/

（1）Ensure that the mobile phone has previously connected to the WIFI and successfully controlled the unit via WIFI.

（2）With the power disconnected, open the indoor unit panel, remove the WIFI module, and it is recommended to clean the WIFI USB interface using a lint-free cloth.

（3）With the power disconnected, open the indoor unit panel and replace the WIFI module.

（4）If cleaning or replacement is ineffective, attempt to replace the indoor unit main control board.

Note: The E9 error code appears only on models equipped with WIFI functionality.

(1) Replace the indoor main control PCB  assembly or the indoor unit

/

(1) Replace the outdoor main control PCB  assembly or the outdoor unit

/

The indoor unit cross-flow fan uses a DC motor. When the motor's speed feedback signal cannot be received by the indoor unit main control board, the indoor unit will report a "DC Fan Motor Fault," indicated by the error code F0.

Causes for abnormal speed feedback signals include:

① The cross-flow fan blade is jammed or not rotating;

② Internal speed feedback electronic components within the DC motor are damaged;

③ The speed feedback signal receiving circuit on the indoor unit main control board is faulty.

（1）After starting the air conditioner, visually check if the indoor unit cross-flow fan blade rotates normally without mechanical jamming.

（2）If the fan rotates but error F0 is reported after startup, power off the unit, remove the middle frame to locate the cross-flow fan motor. Trace the motor terminal wires to the connection point with the indoor main control board and re-seat the DC fan connector to eliminate the fault caused by a loose connector.

（3）With the power off, disconnect the DC fan motor terminals from the indoor main control board. Use a multimeter to measure the resistance of the DC fan motor terminal plug to confirm if the wiring is open or closed.

（4）If the above steps fail to identify the issue, attempt to replace the DC fan motor.

（5）If replacing the DC fan motor is ineffective, replace the indoor unit main control board or the entire indoor unit directly.

（2）Inspect whether the connection between the indoor ambient temperature sensor plug and the indoor main control board is secure and free of looseness.

（3）Eliminate environmental factors: Check for possible causes such as water ingress, moisture, or high temperature.

（4）With the power off, disconnect the indoor ambient temperature sensor from the main control board. Use a multimeter to measure the resistance at the sensor terminals (should be approximately 10KΩ at 77℉). If the measured resistance is approximately 0KΩ, it indicates a short circuit, and the sensor should be replaced. If the reading shows ∞, it indicates an open circuit; inspect the wiring harness or the sensor.

（5）If all the above are normal, replace the components in the following order: Indoor ambient temperature sensor → Indoor unit main control board → Indoor unit.

Abnormalities in the indoor unit Ambient sensor may result in the following issues:

（1）Detected temperature is significantly lower than actual temperature: This can cause continuous operation (failure to shut down) during heating mode and failure to start during cooling mode.

（2）Detected temperature is significantly higher than actual temperature: This can result in failure to start during heating mode and continuous operation (failure to shut down) during cooling mode.

（3） Open Circuit: This indeed refers to a broken circuit, such as wire breakage, poor contact, blown fuses, or relay contacts failing to close, preventing current from forming a loop. In air conditioning systems, this is commonly seen in disconnected sensors, open-start capacitors for compressors, or broken traces on control boards.

Short Circuit: A short circuit refers to an abnormal low-impedance connection between two points in a circuit. This causes current to bypass the normal path (especially bypassing the load), resulting in a substantial increase in current flow.

（2）Inspect the connection between the outdoor unit ambient temperature sensor plug and the outdoor unit main control board to ensure it is secure and not loose.

（3）Eliminate environmental factors: Check for possible causes such as water ingress, moisture, or high temperatures.

（4）After disconnecting the power, detach the outdoor unit ambient temperature sensor from the main control board and use a multimeter to measure the resistance at the sensor terminals. The resistance should be approximately 10KΩ at 77℉. If the reading is approximately 0KΩ, it indicates a short circuit, and the sensor needs replacement. If the reading shows ∞ (infinite), it indicates an open circuit; inspect the wiring or the sensor.

（5）If all the above are normal, replace the components in the following order: Outdoor unit ambient temperature sensor → Outdoor unit main control board → Outdoor unit.

（1）Open Circuit: This indeed refers to a broken circuit, such as wire breakage, poor contact, blown fuses, or relay contacts failing to close, preventing current from forming a loop. In air conditioning systems, this is commonly seen in disconnected sensors, open-start capacitors for compressors, or broken traces on control boards.

（2）Short Circuit: A short circuit refers to an abnormal low-impedance connection between two points in a circuit. This causes current to bypass the normal path (especially bypassing the load), resulting in a substantial increase in current flow.

（1）Check wiring continuity: Verify the integrity of the wiring between the indoor unit coil sensor and the indoor unit main control board.

（2）Inspect whether the connection between the indoor unit coil sensor plug and the main control board is secure and free of looseness.

（3）Eliminate environmental factors: Check for possible causes such as water ingress, moisture, or high temperature.

（4）With the power off, disconnect the indoor unit coil sensor from the main control board. Use a multimeter to measure the resistance at the sensor terminals (should be approximately 10KΩ at 77℉). If the measured resistance is approximately 0KΩ, it indicates a short circuit, and the sensor should be replaced. If the reading shows ∞, it indicates an open circuit; inspect the wiring harness or the sensor.

（5）If all the above are normal, replace the components in the following order: Indoor unit coil sensor → Indoor unit main control board → Indoor unit.

Abnormalities in the indoor unit coil sensor may result in the following issues:

(1) Detected temperature is significantly lower than actual temperature: This can lead to high system pressure due to anti-cold-wind protection mechanisms during heating mode, and frequent frost protection cycles during cooling mode.

(2) Detected temperature is significantly higher than actual temperature: This can trigger frequent high-temperature protection during heating mode and overload protection during cooling mode.

(3) Open Circuit: This indeed refers to a broken circuit, such as wire breakage, poor contact, blown fuses, or relay contacts failing to close, preventing current from forming a loop. In air conditioning systems, this is commonly seen in disconnected sensors, open-start capacitors for compressors, or broken traces on control boards.

Short Circuit: A short circuit refers to an abnormal low-impedance connection between two points in a circuit. This causes current to bypass the normal path (especially bypassing the load), resulting in a substantial increase in current flow.

（1）Check wiring continuity: Verify that the wiring between the outdoor unit coil sensor and the outdoor unit main control board is intact.

（2）Inspect the connection between the outdoor unit coil sensor plug and the outdoor unit main control board to ensure it is secure and not loose.

（3）Eliminate environmental factors: Check for possible causes such as water ingress, moisture, or high temperatures.

（4）After disconnecting the power, detach the outdoor unit coil sensor from the main control board and use a multimeter to measure the resistance at the sensor terminals. The resistance should be approximately 10KΩ at 77℉. If the reading is approximately 0KΩ, it indicates a short circuit, and the sensor needs replacement. If the reading shows ∞ (infinite), it indicates an open circuit; inspect the wiring or the sensor.

（5）If all the above are normal, replace the components in the following order: Outdoor unit coil sensor → Outdoor unit main control board → Outdoor unit.

Abnormalities in the outdoor unit coil sensor may result in the following issues:

(1) Detected temperature is significantly lower than actual temperature: This can cause frequent false defrost cycles during heating mode and loss of protection mechanisms during cooling mode.

(2) Detected temperature is significantly higher than actual temperature: This can result in no defrosting during heating mode and frequent protective shutdowns during cooling mode.

(3) Open Circuit: This indeed refers to a broken circuit, such as wire breakage, poor contact, blown fuses, or relay contacts failing to close, preventing current from forming a loop. In air conditioning systems, this is commonly seen in disconnected sensors, open-start capacitors for compressors, or broken traces on control boards.

Short Circuit: A short circuit refers to an abnormal low-impedance connection between two points in a circuit. This causes current to bypass the normal path (especially bypassing the load), resulting in a substantial increase in current flow.

（1）Check wiring continuity: Verify that the wiring between the outdoor unit exhaust sensor and the outdoor unit main control board is intact.

（2）Inspect the connection between the outdoor unit discharge sensor plug and the outdoor unit main control board to ensure it is secure and not loose.

（3）Eliminate environmental factors: Check for possible causes such as water ingress, moisture, or high temperatures.

（4）After disconnecting the power, detach the outdoor unit discharge sensor from the main control board and use a multimeter to measure the resistance at the sensor terminals. The resistance should be 60KΩ at 77℉. If the reading is approximately 0KΩ, it indicates a short circuit, and the sensor needs replacement. If the reading shows ∞ (infinite), it indicates an open circuit; inspect the wiring or the sensor.

（5）If all the above are normal, replace the components in the following order: Outdoor unit discharge sensor → Outdoor unit main control board → Outdoor unit.

/

（1）Check if the indoor unit and outdoor unit models match by verifying the nameplates.

（2）Inspect whether the communication wiring between the indoor and outdoor units is correctly connected according to the installation manual, ensuring there are no incorrect connections, looseness, damage, or poor contact.

（3）Use a multimeter to measure the voltage across the terminals of the outdoor unit. The voltage between the live wire (L) and neutral wire (N) should be the power input voltage (depending on the model). The voltage between the neutral wire (N) and the communication wire (S) should be a DC voltage ranging from 0-24V. If the measured voltage is abnormal, replace the outdoor main control board.

（4）Prioritize replacing the outdoor unit main control board, followed by the indoor unit main control board if necessary.

/

（1）Replace the outdoor main control PCB  assembly or the outdoor unit

（1）The IPM in air conditioners stands for "Intelligent Power Module." It is a core component of the frequency conversion control system, typically mounted on the large heat sink within the electrical control box, and is primarily responsible for driving the compressor operation.

（1）Shut down the unit and wait for it to automatically recover.

（2）Check if the air outlets of the indoor and outdoor units are unobstructed; inspect whether the filters, evaporators, or condensers are dirty, clogged, or covered with dust.

（3）Check if the indoor unit cross-flow fan blade and the outdoor unit fan blade are rotating normally without abnormalities, and if the airflow is normal (not low). If abnormal, refer to error code F0、E2.

（4）Check voltage: With the power on, use a multimeter to measure the voltage between the terminals on the indoor unit terminal block. Verify that it matches the voltage range specified on the model nameplate (typically within Voltage ±10%) and ensure there is no incorrect connection (e.g., connecting 230V to a 115V model or 115V to a 230V model).

（2）Check if the indoor unit cross-flow fan blade and the outdoor unit fan blade are rotating normally without abnormalities, and if the airflow is normal (not low). If abnormal, refer to error code F0、E2.

（3）Check wiring continuity: Verify that the wiring between the outdoor unit discharge sensor and the outdoor unit main control board is intact.

（4）Inspect the connection between the outdoor unit discharge sensor plug and the outdoor unit main control board to ensure it is secure and not loose.

（5）Eliminate environmental factors: Check for possible causes such as water ingress, moisture, or high temperatures.

（6）After disconnecting the power, detach the outdoor unit discharge sensor from the main control board and use a multimeter to measure the resistance at the sensor terminals. The resistance should be approximately 600KΩ at 77℉. If the reading is approximately 0KΩ, it indicates a short circuit, and the sensor needs replacement. If the reading shows ∞ (infinite), it indicates an open circuit; inspect the wiring or the sensor.

（7）Check if the system pressure is too low: While the unit is running in cooling mode, use a pressure gauge to check the pressure at the outdoor unit's three-way stop valve. (When operating in cooling mode, the low pressure is generally around 0.8–1.0 Mpa (116.03–145.04 PSIG)). If the pressure is significantly lower than 0.8 Mpa (116.0 PSIG), it indicates a refrigerant leak (if recharging is desired, first determine if the product conditions meet the standards for recharging).

（2）Check if the air outlets of the indoor and outdoor units are unobstructed; inspect whether the filters, evaporators, or condensers are dirty, clogged, or covered with dust.

（3）Check if the indoor unit cross-flow fan blade and the outdoor unit fan blade are rotating normally without abnormalities, and if the airflow is normal (not low). If abnormal, refer to error code F0、E2.

（1）During heating operation, if frost forms on the outdoor unit, the air conditioner will automatically enter defrost mode to maintain heating performance. During the defrosting process, both the indoor and outdoor fans will stop running. Once defrosting is complete, the air conditioner will automatically resume heating operation (Typically, the defrost mode will run for approximately 10 minutes.).

（1）Check if the indoor unit air outlet is unobstructed; inspect whether the filter, evaporator, or condenser is dirty or clogged with dust.

（2）Check if the indoor unit cross-flow fan blade is rotating normally without abnormalities and if the airflow is normal (not low). If abnormal, refer to error code F0.

（3）Verify if the indoor unit installation meets the standards specified in the instruction manual.

（4）Check wiring continuity: Ensure the wiring between the indoor unit coil sensor and the indoor unit main control board is intact.

（5）Inspect the connection between the indoor unit coil sensor plug and the indoor unit main control board to ensure it is secure and not loose.

（6）Eliminate environmental factors: Check for possible causes such as water ingress, moisture, or high temperatures.

（7）After disconnecting the power, detach the indoor unit coil sensor from the main control board and use a multimeter to measure the resistance at the sensor terminals. The resistance should be approximately 10KΩ at 77℉. If the reading is approximately 0KΩ, it indicates a short circuit, and the sensor needs replacement. If the reading shows ∞ (infinite), it indicates an open circuit; inspect the wiring or the sensor.

（8）Only after ensuring all of the above are normal, proceed to replace components in the following order: Indoor unit coil sensor → Indoor unit main control board → Indoor unit.

（1）Check if the indoor unit air outlet is unobstructed; inspect whether the filter, evaporator, or condenser is dirty, clogged, or covered with dust.

（2）Check if the indoor unit cross-flow fan blade is rotating normally without abnormalities and if the airflow is normal (not low). If abnormal, refer to error code F0.

（3）Verify if the indoor unit installation meets the standards specified in the instruction manual.

（4）Check wiring continuity: Ensure the wiring between the indoor unit coil sensor and the indoor unit main control board is intact.

（5）Inspect the connection between the indoor unit coil sensor plug and the indoor unit main control board to ensure it is secure and not loose.

（6）Eliminate environmental factors: Check for possible causes such as water ingress, moisture, or high temperatures.

（7）After disconnecting the power, detach the indoor unit coil sensor from the main control board and use a multimeter to measure the resistance at the sensor terminals. The resistance should be approximately 10KΩ at 77℉. If the reading is approximately 0KΩ, it indicates a short circuit, and the sensor needs replacement. If the reading shows ∞ (infinite), it indicates an open circuit; inspect the wiring or the sensor.

（8）Only after ensuring all of the above are normal, proceed to replace components in the following order: Indoor unit coil sensor → Indoor unit main control board → Indoor unit.

（1）Check if the outdoor unit air outlet is unobstructed; inspect whether the filter, evaporator, or condenser is dirty, clogged, or covered with dust.

（2）Check if the outdoor unit fan blade is rotating normally without abnormalities and if the airflow is normal (not low). If abnormal, refer to error code E2.

（3）Verify if the outdoor unit installation meets the standards specified in the instruction manual.

（4）Check wiring continuity: Ensure the wiring between the outdoor unit coil sensor and the outdoor unit main control board is intact.

（5）Inspect the connection between the outdoor unit coil sensor plug and the outdoor unit main control board to ensure it is secure and not loose.

（6）Eliminate environmental factors: Check for possible causes such as water ingress, moisture, or high temperatures.

（7）After disconnecting the power, detach the outdoor unit coil sensor from the main control board and use a multimeter to measure the resistance at the sensor terminals. The resistance should be approximately 10KΩ at 77℉. If the reading is approximately 0KΩ, it indicates a short circuit, and the sensor needs replacement. If the reading shows ∞ (infinite), it indicates an open circuit; inspect the wiring or the sensor.

（8）Check if the system pressure is too high: Use a pressure gauge to check the pressure at the outdoor unit's three-way stop valve. (When the product is running in cooling mode, the low pressure is generally around 0.8–1.0 Mpa (116.03–145.04 PSIG)). If the pressure is significantly higher than 1.0 Mpa (145.04 PSIG), it indicates a blockage in the air conditioning system. Try powering off for 10 minutes and then restarting. If the indoor unit continues to report error code P6, replace the outdoor unit first, then the indoor unit.

（9）Only after ensuring all of the above are normal, proceed to replace components in the following order: Outdoor unit coil sensor → Outdoor unit main control board → Outdoor unit.

Outdoor Unit over-high/over-low 

AC voltage protection

（1）Check voltage: With the power on, use a multimeter to measure the voltage between the terminals on the indoor unit terminal block. Verify that it matches the voltage range specified on the model nameplate (typically within Voltage ±10%) and ensure there is no incorrect connection (e.g., connecting 230V to a 115V model or 115V to a 230V model).

（2）Check if the outdoor unit air outlet is unobstructed; inspect whether the filter, evaporator, or condenser is dirty, clogged, or covered with dust.

（3）Check if the system pressure is too high: Use a pressure gauge to check the pressure at the outdoor unit's three-way stop valve. (When the product is running in cooling mode, the low pressure is generally around 0.8–1.0 Mpa (116.03–145.04 PSIG)). If the pressure is significantly higher than 1.0 Mpa (145.04 PSIG), it indicates a blockage in the air conditioning system. Try powering off for 10 minutes and then restarting. If the indoor unit continues to report error code P7, replace the outdoor unit first, then the indoor unit.

Outdoor Unit over-high/over-low 

DC voltage protection

（1）Check voltage: With the power on, use a multimeter to measure the voltage between the terminals on the indoor unit terminal block. Verify that it matches the voltage range specified on the model nameplate (typically within Voltage ±10%) and ensure there is no incorrect connection (e.g., connecting 230V to a 115V model or 115V to a 230V model).

（2）Check if the outdoor unit air outlet is unobstructed; inspect whether the filter, evaporator, or condenser is dirty, clogged, or covered with dust.

（3）Check if the system pressure is too high: Use a pressure gauge to check the pressure at the outdoor unit's three-way stop valve. (When the product is running in cooling mode, the low pressure is generally around 0.8–1.0 Mpa (116.03–145.04 PSIG)). If the pressure is significantly higher than 1.0 Mpa (145.04 PSIG), it indicates a blockage in the air conditioning system. Try powering off for 10 minutes and then restarting. If the indoor unit continues to report error code P8, replace the outdoor unit first, then the indoor unit.

IPM over-high temperature protection

（1）Shut down the unit and wait for it to automatically recover.

（2）Check if the air outlets of the indoor and outdoor units are unobstructed; inspect whether the filters, evaporators, or condensers are dirty, clogged, or covered with dust.

（3）Check if the indoor unit cross-flow fan blade and the outdoor unit fan blade are rotating normally without abnormalities, and if the airflow is normal (not low). If abnormal, refer to error code F0、E2.

Outdoor unit ambient temperature over-low protection(Cooling Mode)

（1）First, determine if the system's self-protection function is triggered by a normal phenomenon, i.e., whether the outdoor ambient temperature is lower than the minimum limit that the indoor and outdoor units can withstand (refer to the instruction manual).

（2）Check if the entire air conditioning system has been running continuously at high load or overload for an extended period.

（3）Check wiring continuity: Verify that the wiring between the outdoor unit ambient temperature sensor and the main control board is intact.

（4）Inspect the connection between the outdoor unit ambient temperature sensor plug and the outdoor unit main control board to ensure it is secure and not loose.

（5）Eliminate environmental factors: Check for possible causes such as water ingress, moisture, or excessively high temperatures.

（6）After disconnecting the power, detach the outdoor unit ambient temperature sensor from the main control board and use a multimeter to measure the resistance at the sensor terminals. The resistance should be approximately 10KΩ at 77℉. If the reading is approximately 0KΩ, it indicates a short circuit, and the sensor needs replacement. If the reading shows ∞ (infinite), it indicates an open circuit; inspect the wiring or the sensor.

Outdoor unit Ambient temperature over-high protection(Heating Mode)

（1）First, determine if the system's self-protection function is triggered by a normal phenomenon, i.e., whether the outdoor ambient temperature exceeds the maximum limit that the indoor and outdoor units can withstand (refer to the instruction manual).

（2）Check if the entire air conditioning system has been running continuously at high load or overload for an extended period.

（3）Check wiring continuity: Verify that the wiring between the outdoor unit ambient temperature sensor and the main control board is intact.

（4）Inspect the connection between the outdoor unit ambient temperature sensor plug and the outdoor unit main control board to ensure it is secure and not loose.

（5）Eliminate environmental factors: Check for possible causes such as water ingress, moisture, or high temperatures.

（6）After disconnecting the power, detach the outdoor unit ambient temperature sensor from the main control board and use a multimeter to measure the resistance at the sensor terminals. The resistance should be approximately 10KΩ at 77℉. If the reading is approximately 0KΩ, it indicates a short circuit, and the sensor needs replacement. If the reading shows ∞ (infinite), it indicates an open circuit; inspect the wiring or the sensor.