Diagnostics show E12; condenser temperature or ambient sensor fault; unit may run excessively.

Safety first: Disconnect power before accessing the rear compartment or control board.

Steps to resolve:

• Locate sensor: The ambient or condenser sensor is often near the condenser coils or compressor area.
• Inspect wiring: Look for melted insulation, rodent damage, or loose connectors.
• Secure sensor: Ensure the sensor is properly mounted and not dangling or touching hot components directly.

If E12 persists, the sensor should be tested and replaced if out of specification. If a new sensor does not clear the code, the main control board may be defective and requires professional diagnosis.