Error Code: EC 50 – Open or Short Circuit of Outdoor Temperature Sensor (T3, T4, TP)

Error Code: EC 50 – Open or Short Circuit of Outdoor Temperature Sensor (T3, T4, TP)

What this means:
The system has detected that one or more of the outdoor temperature sensors — T3 (coil), T4 (ambient), or TP (compressor discharge) — is either disconnected (open circuit) or shorted. This prevents accurate temperature monitoring, and the unit shuts down to avoid risk of damage.

Try this first (quick reset):

1. Turn off power to the unit completely.

2. Wait 2 full minutes.

3. Turn the unit back on and check if the error clears.

• If the error clears — the fault may have been temporary.

• If the error remains — continue with the steps below.

Next steps (for technicians):

1. Check sensor connections to the PCB:

   • Ensure all wires for T3, T4, and TP are properly seated and undamaged.

2. Measure resistance of each sensor (T3, T4, TP):

   • If the resistance is not within range → replace the faulty sensor.

3. If all sensors are within spec but the error persists:

   • Replace the outdoor main PCB.

What you might need:

• Combination temperature sensor (T3/T4/TP, if used)

• Outdoor main PCB

• Connection wires

Helpful tip:
Some models use a combination sensor for T3, T4, and TP. Always check your unit’s design before ordering parts. This error is triggered when sensor voltage is below 0.06V or above 4.94V.

Click here to view the detailed guide.TS05-ODU