Evaporator Coil Temperature 4 Sensor Failure

What does Evaporator Coil Temperature 4 Sensor Fail mean?

This alarm indicates a failure with the Evaporator Coil Temperature 4 (EC4) sensor, likely due to an open circuit or exceeding its input range. This sensor protects the compressor.

• Faulty EC4 sensor
• Damaged wiring harness to the EC4 sensor
• SEC board issue

Click steps to track your progress.

1. 1

   Check the EC4 sensor reading on the board or via the Map Gateway tool (Details > Service > Inputs > CoilSensors > EC4=value).

2. 2

   Unplug the EC4 sensor wires from the SEC board and check resistance to the sensor to verify temperature reading.

3. 3

   If resistance is incorrect, trace wires to the plug and ohm from the plug to the sensor.

4. 4

   Repair or replace the wiring harness if damaged.

5. 5

   Replace the sensor if the harness is fine but the reading is still incorrect.

6. 6

   Replace the SEC board if both harness and sensor are functional.