John Deere 876.1 – ATC (Automatic Temperature Control): Excessive A/C Clutch Cycling

The controller generates this code when the air-conditioning compressor clutch engages and disengages more than six times per minute. When this code is active, the controller's reaction is to restrict temperature control, and the compressor clutch (M02) is prevented from switching on to protect the system.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6020 to 6920S
• 6120 to 6420
• 6120L to 6520L
• 7715
• 7815
• 7720
• 7820
• 7920
• 8120
• 8220
• 8320
• 8420
• 8520
• 8130
• 8230
• 8330
• 8430
• 8530
• 8230T
• 8330T
• 8430T
• 8310RT
• 8335RT
• 8360RT
• 9320T
• 9420T
• 9520T
• 9620T
• 9470RT
• 9520RT
• 9570RT
• 9230
• 9330
• 9430
• 9530
• 9630

1. 1

   Check refrigerant pressure using manifold gauges, as rapid cycling is most commonly caused by a low refrigerant charge

2. 2

   Test the A/C Relay (K09/4) and its circuit/harness for a shorted or open condition

3. 3

   Test the A/C pressure switch (B15) and thermostat switch (B14) to see if they are opening and closing erratically

1. 1

   Verify Refrigerant Levels

   Connect A/C manifold gauges to the high and low service ports.

2. 2

   Leak Test and Recharge

   If the pressure is low, inspect the system for leaks. Recover any remaining refrigerant, repair the leak, evacuate the system, and recharge it with the factory-specified amount of R134a refrigerant.

3. 3

   Inspect/Replace Relay K09/4

   If the refrigerant level is correct, locate the A/C relay (K09/4) in the relay box (often K10). Swap it with a known good relay of the same type to see if the rapid cycling stops. Replace if faulty.

4. 4

   Inspect/Replace Pressure Switch

   If the relay is good, test the A/C pressure switch (B15). If it is failing and sending erratic signals to the clutch, evacuate the system (if the switch is not on a Schrader valve) and replace the switch.

5. 5

   Clear Codes

   Once repairs are made, restart the tractor. Some codes can be corrected by resetting the communication messages when the tractor is restarted, or by acknowledging the code on the CommandCenter/Service ADVISOR to clear the display. Run the A/C to verify the clutch cycles normally (less than 6 times per minute).