Case IH 1079 – ARM (Armrest Controller): Invalid Configuration - Diff lock switch is failed

The controller has detected an illogical state, open circuit, or short to ground originating from the differential lock rocker switch.

• MX Magnum
• STX Steiger
• Case IH Magnum Series
• Series 4 Magnum 235-340
• Case IH Steiger Series
• Case IH Puma Series
• Case IH TG Series

1. 1

   Verify that fault code ARM 1079 is actively present at the armrest controller.

2. 2

   Perform an operational icon test by turning the Diff Lock switch ON and OFF in the armrest. Watch the display monitor to see if the Diff Lock icon turns ON and OFF accordingly.

3. 3

   Depress both brake pedals while watching the display to see if the system responds (depressing both brakes typically disengages the diff lock).

4. 4

   Inspect the switch's electrical connector ends for damaged, bent, or dislocated pins.

5. 5

   Test the wiring harness between the switch and the armrest controller for an open circuit or a short to ground.

1. 1

   Power down the tractor and disconnect the battery to prevent electrical shorts.

2. 2

   Carefully remove the necessary trim panels on the right-hand armrest console to access the underside of the switch panel.

3. 3

   Locate the Differential Lock rocker switch and disconnect its electrical harness connector.

4. 4

   Depress the retaining tabs on the sides of the faulty switch body and push it upward/outward to remove it from the armrest bezel.

5. 5

   Snap the new OEM differential lock switch into the armrest panel until it clicks securely into place.

6. 6

   Reconnect the electrical harness to the new switch.

7. 7

   Reassemble the armrest trim panels.

8. 8

   Reconnect the battery, power on the tractor, and clear the stored fault codes.

9. 9

   Actuate the new switch to ensure the Diff Lock icon illuminates on the display and verify that code ARM 1079 does not return.