LG Washer Error Code tC4

The tC4 code indicates a temperature sensor error related to the inverter printed board (PB). It triggers when the motor driver in the inverter PB reaches a high temperature, or when the IPM thermistor reads an OPEN or SHORT condition. The inverter PB controls the motor speed, and the IPM thermistor monitors its temperature to prevent thermal damage. The washer stops operation to protect the motor electronics.

It is not recommended to continue running the washer while tC4 is active. The error indicates either a genuine overheating condition or a faulty temperature sensor in the motor control circuit. Running the washer without resolving the fault could cause further damage to the inverter PB or motor. Stop use until the cause has been identified and corrected.

Repair costs depend on whether the inverter PB needs to be replaced and whether labor is required. Inverter PB parts for LG washers typically range from $80 to $200 or more depending on the model. With professional labor, total repair costs generally fall in the range of $150 to $350. Getting a diagnostic service call first is advisable to confirm the failed component before purchasing parts.

Some basic checks, such as ensuring the washer has proper ventilation and inspecting for obvious heat damage, can be done without specialized tools. However, diagnosing and replacing the inverter PB involves working with high-voltage components and requires electrical testing equipment. Most homeowners should have a qualified technician handle inverter PB diagnosis and replacement.

A power reset may temporarily clear the code, but if the underlying fault in the inverter PB or IPM thermistor is still present, the error will return. Resetting without repairing the root cause is not a long-term solution and could allow the condition to worsen. The inverter PB should be inspected and tested before returning the unit to regular use.