Whirlpool Microwave Error Code FCE2

The FCE2 error code on a Whirlpool microwave indicates a failure in the exhaust air temperature detection circuit, specifically involving the HF NTC thermistor. This thermistor is a negative temperature coefficient sensor responsible for monitoring the temperature of exhaust air moving through the microwave's ventilation system. The Appliance Control Unit (ACU) continuously reads the resistance signal from this thermistor to ensure safe operating temperatures. When the ACU detects a signal that falls outside acceptable parameters, it flags the FCE2 code and may disable normal operation to prevent potential overheating.

The primary diagnostic method for FCE2 involves measuring the resistance across the HF NTC thermistor connector pins after disconnecting the cable from the ACU. At room temperature, the correct resistance reading should fall between 9.5 k ohms and 10.5 k ohms. A reading outside this range confirms the thermistor itself has failed. A reading of infinite resistance suggests an open circuit, while a reading near zero indicates a short. Both conditions would cause the ACU to log the FCE2 fault.

Common root causes include a failed thermistor, damaged wiring harness, corroded connector pins, or a faulty ACU that misreads an otherwise functional sensor. Because the thermistor monitors exhaust air, physical blockages or grease buildup near the sensor can also accelerate thermistor degradation over time. Proper diagnosis requires entering the microwave's Diagnostics mode first to confirm the code is active and matches the reported complaint before proceeding with component testing.