Diagnostic mode shows E1 and fresh food temperature control is erratic or inaccurate.

Safety first: Unplug the refrigerator before accessing sensors or the control board.

• Locate the thermistor: In GE refrigerators, the fresh food thermistor is usually behind a small plastic cover on the rear wall or ceiling of the refrigerator compartment.
• Inspect wiring: Remove the cover and check the thermistor and its wires for damage or loose connections.
• Test thermistor: Disconnect the thermistor and measure resistance with a multimeter at a known temperature (e.g., in ice water ~32°F). Compare to GE's thermistor chart. If readings are open, shorted, or far off spec, replace the thermistor.
• Check board connection: At the main control board, verify the thermistor connector is fully seated and not corroded.
• Control board: If a known-good thermistor still reads as an error, the control board input may be defective and require replacement.