Case IH 6025 (564.04) - DEC – DEC: 2WD Solenoid - short to GND

The electrical circuit controlling the 2WD (Two-Wheel Drive / Front-Wheel Drive disengage) solenoid has a short to ground (GND). The voltage intended to power the solenoid coil is finding a premature path directly to the tractor's chassis ground, preventing the solenoid from energizing properly and resulting in the tractor defaulting to 4WD/MFWD mode.

• VESTRUM CVX
• Steiger Series
• Magnum & MX/TG Series
• Puma & Maxxum Series

1. 1

   Inspect the wiring harness running from the DEC to the 2WD/FWD solenoid for pinched wires, melted insulation, or chafing against the tractor chassis.

2. 2

   Perform a solenoid swap test by swapping the 2WD solenoid coil with an identical adjacent solenoid (such as the differential lock solenoid) to isolate the issue.

3. 3

   Perform a multimeter resistance test by disconnecting the 2WD solenoid and measuring the resistance across its pins (a reading of near 0 ohms confirms an internal short).

4. 4

   Perform a harness continuity test with the solenoid and DEC disconnected by testing the signal wire for continuity to the chassis ground.

1. 1

   Power Down

   Turn off the tractor and disconnect the negative battery cable to prevent electrical spikes during repair.

2. 2

   Locate the Solenoid

   Locate the FWD/2WD control valve block, which is typically mounted on the side of the transmission housing or near the front-wheel-drive drop box.

3. 3

   Disconnect Wiring

   Unplug the electrical connector from the 2WD solenoid. Clean the connector with electrical contact cleaner to ensure no moisture or debris is bridging the pins.

4. 4

   Repair Wiring

   If the diagnostic tests revealed a chafed wire, cut out the damaged section, splice in a new wire using heat-shrink butt connectors, and wrap the harness in protective loom.

5. 5

   Replace Solenoid

   If the solenoid failed the swap test or resistance test, remove the retaining nut at the end of the solenoid stem. Slide the old electromagnetic coil off the valve cartridge.

6. 6

   Install New Part

   Slide the new OEM solenoid coil onto the valve stem. Install and tighten the retaining nut to the specified torque value (do not overtighten, as this can distort the valve).

7. 7

   Reassembly

   Reconnect the electrical harness to the new solenoid. Reconnect the battery.

8. 8

   Clear Codes

   Turn the ignition on and use the tractor's diagnostic display (or a connected service tool) to clear the stored 6025 fault code. Test drive the machine to verify that 4WD engages and disengages correctly.