John Deere 000876.12 – ATC / VCU: Compressor Clutch Current Present When Off

This diagnostic trouble code is triggered when the compressor clutch (M02) is commanded OFF, but the Power Module (PC6) still measures in excess of 1 amp at the compressor clutch output (specifically on lead 2023). This indicates either a short circuit in the PC6 wiring or an internal fault within the power module itself.

• 6230
• 6330
• 6430
• 7130
• 7230
• 7330
• 7430
• 7530
• 3520
• 3522

1. 1

   Isolate the clutch: Disconnect the A/C compressor clutch (M02) electrical connector, clear the codes, and cycle the A/C system. If the code returns immediately, the issue is in the wiring or the module.

2. 2

   Inspect wiring (Lead 2023): Trace lead 2023 from the PC6 Power Module to the compressor clutch. Check for chafing, melted insulation, or areas where the wire might be shorting to power or ground.

3. 3

   Test the Power Module (PC6): With the clutch disconnected and the A/C commanded off, use a multimeter to check for voltage/current at the clutch connector. If power is still being supplied, the PC6 Power Module has an internal short (stuck relay/driver).

4. 4

   Test the compressor clutch: If the wiring and module test fine, check the resistance of the compressor clutch coil. An internally shorted clutch coil can draw excessive current and damage the module circuit.

1. 1

   Disconnect battery

   Always disconnect the negative battery terminal before servicing electrical components or modules.

2. 2

   Repair wiring

   If a short is found in lead 2023, repair the damaged section of the wiring harness using weather-sealed heat shrink connectors, or replace the affected harness section.

3. 3

   Replace compressor clutch

   If the clutch coil is internally shorted: Remove the serpentine belt and the center bolt holding the clutch hub to the compressor. Use a puller to remove the clutch hub, snap rings, pulley, and the electromagnetic coil. Install the new coil, pulley, and hub, ensuring the proper air gap is set (usually via shims) before reinstalling the center bolt and belt.

4. 4

   Replace PC6 Power Module

   If the module is outputting current when commanded off (internally faulted): Locate the PC6 module, disconnect its harness connectors, and swap in a replacement module.

5. 5

   Clear codes and test

   Reconnect the battery, clear the stored 000876.12 code, and run the A/C system to verify the compressor cycles on and off correctly without triggering the fault.