John Deere 871.03 – ATC: Refrigerant Pressure Sensor Circuit Voltage High

The ATC control unit has detected a voltage exceeding 5 volts at the signal input for the refrigerant pressure sensor (B130, lead 2019), indicating a short to a supply lead. To protect the system, the controller restricts temperature control and automatically de-activates the A/C compressor clutch (M02).

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6120-6420
• 6120L-6520L
• 7715
• 7815
• 7720
• 7820
• 7920
• 8230T
• 8330T
• 8430T
• 9430
• 9530
• 9630
• 8245R
• 8320R
• 9460R
• S550
• S650
• S670
• S680
• S690
• S760
• S770
• S780
• S790
• 444
• 544
• 644
• 744
• 844
• Forwarders
• Harvesters

1. 1

   Restart the engine to verify if the active Service Code reappears, as communication glitches can trigger false codes.

2. 2

   Carefully check the wiring harness and connectors for damage, chafing, or signs of a short circuit, particularly around lead 2019 and the B130 sensor.

3. 3

   Use a multimeter to confirm the voltage level at the sensor's input; a consistent reading above 5 volts validates the presence of a short to a power supply.

4. 4

   Unplug the sensor to isolate it: if the voltage on the signal wire drops to normal reference levels, the sensor itself has failed internally; if the voltage remains above 5V on the harness side, the wiring harness is shorted to power.

1. 1

   Power Down

   Turn off the machine and disconnect the battery to ensure safety while working on the electrical system.

2. 2

   Locate Sensor B130

   Find the Refrigerant Pressure Sensor on the high-side A/C line.

3. 3

   Repair Wiring (If Applicable)

   If diagnostic checks revealed a short to a supply lead in the wiring harness, repair or replace the damaged section of the wiring harness. Ensure all connections are secure and properly insulated.

4. 4

   Replace the Sensor (If Applicable)

   If the wiring tests good but the sensor is outputting out-of-range high voltage, replace the B130 sensor. (Note: Many modern John Deere pressure transducers sit on a Schrader valve, allowing replacement without discharging the A/C system. Verify this on your specific model before unscrewing the sensor).

5. 5

   Reassemble

   Plug the harness back into the sensor and reconnect the battery.

6. 6

   Clear Codes and Test

   Turn the key on, clear any stored ATC fault codes via the CommandCenter display, and start the engine. Engage the A/C system to ensure the compressor clutch engages and the cabin cools properly.