Daikin Air Conditioner Error Code J5

The J5 code means the suction pipe thermistor has been detected as either disconnected or short-circuited during operation. This thermistor monitors the refrigerant temperature on the suction line and sends that data to the main PCB. When the PCB receives a reading outside the valid resistance range, it triggers J5 and shuts the unit down to protect the compressor. Diagnosis involves checking the connector and measuring the thermistor resistance directly.

No. The J5 fault causes the unit to shut down specifically because operating without accurate suction pipe temperature data can lead to compressor damage. You should not attempt to bypass or ignore the fault. Leave the unit off until the thermistor issue has been diagnosed and corrected.

A power reset may temporarily clear the J5 code, but the fault will return during operation if the underlying thermistor problem has not been fixed. Repeated resets without addressing the root cause will not resolve the issue and may mask a developing problem. The thermistor connector and resistance should be checked before relying on a reset to restore normal operation.

A homeowner with basic electrical knowledge can safely check whether the thermistor connector has come loose and reseat it, which sometimes clears the fault. However, measuring thermistor resistance and working near refrigerant components typically requires familiarity with HVAC systems and a multimeter. If the thermistor itself has failed, replacing it requires accessing internal components, which is best handled by a qualified technician.

If the fix is simply reseating a loose connector, the cost is limited to a service call fee, typically in the range of $75 to $150 depending on your area. If the suction pipe thermistor needs replacement, parts and labor combined generally range from $150 to $350. A PCB replacement, if required in rare cases, can push costs significantly higher.