Case IH 2769 (518652.02) - DEC – DEC: SF2 Difflock

Fault within the Differential Lock control circuit. The fault likely indicates an open circuit, short to ground, or mechanical failure in this specific solenoid/relay circuit.

• VESTRUM CVX
• Steiger
• Magnum
• Maxxum

1. 1

   Check the Cab Switch: Verify that the momentary difflock switch on the console/armrest is functioning.

2. 2

   Check the Brake Pedal Switches: Inspect the normally-closed switches under the brake pedals to ensure they are not stuck open or failing to return fully, which would prevent the difflock from engaging.

3. 3

   Test the Relay and Solenoid: Apply direct power (via a jumper wire) to the difflock solenoid located near the hydraulic pump/axle housing to see if it actuates. Test the Bosch-style relay in the fuse panel that powers the solenoid.

4. 4

   Check for Internal Hydraulic Leaks: If the electrical circuit is intact but the difflock fails to hold, check the front/rear axle oil levels. A blown difflock piston seal can cause hydraulic oil to leak directly into the axle housing.

1. 1

   Locate solenoid

   Locate the difflock solenoid valve on the transmission or axle housing.

2. 2

   Inspect wiring harness

   Disconnect the wiring harness and inspect the pins for corrosion or pushed-out terminals.

3. 3

   Test solenoid coil

   If the solenoid coil tests out of specification (open or shorted), remove the retaining nut and slide the coil off the valve stem.

4. 4

   Replace solenoid coil

   Replace the solenoid coil and torque the retaining nut to spec.

5. 5

   Replace brake pedal switches

   If the brake pedal interrupt switches are faulty, remove the lower dash/pedal cover, unbolt the faulty switch, and install a new one, ensuring the pedal arm fully depresses the switch plunger when released.

6. 6

   Clear fault codes

   Clear the fault codes via the tractor's display monitor or diagnostic tool.