John Deere 001547.03 – ETC: A/C Evaporator Probe High Voltage

The Air Conditioning Module (ETC) has detected a voltage on the air conditioning evaporator temperature sensor circuit that is higher than the normal operating range. This typically indicates an open circuit in the wiring harness or a failure within the sensor itself. The sensor monitors the evaporator core temperature to prevent freezing and regulate cabin climate; a failure will disrupt proper A/C operation.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 7R Series
• 8R Series
• 9R Series
• Sprayers

1. 1

   Access the diagnostic menu on the tractor's display to confirm if the fault code is active. Clear the code, operate the A/C system, and check if it reappears.

2. 2

   Visually inspect the wiring harness and connectors between the evaporator temperature sensor and the A/C control module for damage, corrosion, or loose connections.

3. 3

   Perform a sensor voltage test: With the key on and sensor disconnected, check for a 5V reference voltage at the sensor's connector. Lack of voltage indicates an issue further up the harness or in the control module.

4. 4

   Perform a sensor resistance test: Disconnect the sensor and measure its resistance with a multimeter. The resistance should change when the sensor is warmed or cooled. An infinite resistance reading indicates an open circuit within the sensor.

1. 1

   Safety First

   Lower all equipment to the ground, stop the engine, and disconnect the battery ground strap.

2. 2

   Access the Sensor

   Locate the evaporator temperature sensor within the HVAC housing, inserted into the evaporator core. Access may require removing panels in the cab roof or operator's station.

3. 3

   Perform Diagnostics

   Conduct the voltage and resistance tests as described above to confirm whether the fault lies with the sensor, the wiring, or the controller.

4. 4

   Repair Wiring

   If a wiring issue is found, repair the damaged section or replace the faulty connector.

5. 5

   Replace the Sensor

   If the sensor is determined to be faulty, it should be replaced. The sensor is typically held in place by a simple locking tab and can be rotated and pulled out.

6. 6

   Reassemble and Test

   After replacing the sensor or repairing the wiring, reassemble all components, reconnect the battery, and operate the air conditioning system to ensure it is functioning correctly. Check for any returning fault codes.