Error 12 — Outdoor ambient temperature sensor fault

What does 12 mean?

There is an electrical failure with the sensor that measures the outdoor air temperature. This sensor connects to the PCB via two wires at Plug CN-14.

• Loose sensor connection
• Open or shorted sensor
• Sensor is out of calibration
• Faulty sensor wiring

Click steps to track your progress.

1. 1

   Check the connection at Plug CN-14 for the outdoor ambient temperature sensor.

2. 2

   Inspect the sensor wiring for damage.

3. 3

   Test the sensor resistance against calibration tables.

4. 4

   Replace the sensor if faulty or out of calibration.