This is for the GE refrigerators that have the muthaboard in back and at least 5 pads on the touch control panel.
To enter Self Diagnostic mode, both temperature control panel displays must be illuminated.
A display can be illuminated by pressing an adjacent temperature adjustment button.
When both displays are illuminated, set the freezer and refrigerator temperature settings to 5.
Simultaneously press and hold all 4 temperature adjustment buttons for approximately 3 seconds.
A flashing 0 in the refrigerator and freezer displays will indicate that the refrigerator is in Self Diagnostic mode.
Use the freezer temperature adjustment buttons to enter the test code number in the freezer display.
Use the refrigerator temperature adjustment buttons to enter the test code number in the refrigerator display.
When a test code has been entered, the displays will flash to confirm the test.
Press the HOLD button for 3 seconds to begin the test.
Freezer . . . . . Fridge
. . 1. . . . . . . . . . 4
If the cabinet is not cold when executed, this mode may execute extremely fast.
The refrigerator will return to normal operation on its own.
When testing has been completed, do one of the following things:
• Enter code 1 5 to completely reset the system.
• Enter code 1 6 to exit diagnostic mode. The temperature control panel is reset automatically.
• Unplug the refrigerator for at least 10 seconds. Test mode will terminate when the refrigerator is plugged back in.
Test mode will terminate automatically after 15 minutes of inactivity.
For service manuals and lots of other goodies, become an Apprentice ==> Apprenticeship
Source: Freezer check underway for ice build-up -- defrost heater, thermostat