GE Microwave F4 Error: Sensor Replacement Guide - Solar... | appliancefaults.com

Technical Background:

The F4 error code on a GE microwave typically indicates a fault within the oven temperature sensor circuit. The MCU (Microcontroller Unit) on the control board monitors the sensor's resistance to determine the oven's internal temperature. If the MCU detects an abnormal resistance value (open circuit, short circuit, or out-of-range reading), it triggers the F4 error, stopping the heating process to prevent damage.

Symptoms:

The GE microwave displays an F4 error code on the control panel and may not heat properly or at all. The turntable may also fail to rotate.

Possible Causes:

Faulty oven temperature sensor (thermistor)
Wiring harness issues (loose connections, damaged wires)
Defective control board (MCU)
Sensor improperly mounted or positioned
Excessive heat exposure damaging the sensor
Internal short within the sensor

Solution:

1

Disconnect the microwave from the power outlet. Verify 120V AC power is OFF at the outlet using a multimeter.
2

Locate the oven temperature sensor. It is typically located inside the oven cavity, often near the top or side wall.
3

Disconnect the sensor wiring harness from the sensor.
4

Test the sensor resistance using a multimeter. A typical reading is around 50k ohms at room temperature (70°F). Consult the service manual for the exact specification.
5

If the sensor resistance is outside the specified range, replace the sensor with part number WB24X10205.
6

Reconnect the wiring harness to the new sensor and ensure it is securely fastened.
7

Plug the microwave back into the power outlet and test its operation. Clear the error code, if needed, by unplugging the unit for 60 seconds.

Safety Warning:

Always disconnect the microwave from the power outlet before performing any repairs. High voltage components are present inside the unit. Use extreme caution. LOTO (Lock Out, Tag Out) procedures should be followed when applicable.

Prevention:

Regularly clean the inside of the microwave to prevent food splatters from accumulating on the sensor. Avoid overheating the microwave by using appropriate cooking times and power levels.

Expert Tip:

Some GE microwave models have a service mode. Access it by pressing specific button combinations (refer to the service manual). In service mode, you can often run diagnostic tests on the oven temperature sensor to verify its operation before replacing it.

Frequently Asked Questions

•What is the correct resistance range for the oven temperature sensor at room temperature?

The correct resistance range for the oven temperature sensor at room temperature (around 70°F) is typically around 50k ohms. However, it's always best to consult the service manual for your specific model for the exact specification.

•How do I access the service mode on my GE microwave model?

The procedure for accessing the service mode varies depending on the specific GE microwave model. Refer to the service manual for your model, or search online for the specific button combination required to enter service mode.

•If replacing the sensor doesn't fix the F4 error, what should I check next?

If replacing the sensor doesn't fix the F4 error, the next step is to carefully inspect the wiring harness connecting the sensor to the control board for any signs of damage, loose connections, or corrosion. If the wiring harness is intact, the control board itself may be defective and need to be replaced.

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•What is the correct resistance range for the oven temperature sensor at room temperature?

•How do I access the service mode on my GE microwave model?

•If replacing the sensor doesn't fix the F4 error, what should I check next?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: