Case IH 51109 – Remote Hydraulics Controller (AUX Controller): Invalid Software Instruction Executed

The module's microprocessor attempted to process a corrupt, unrecognized, or invalid software command, indicating an internal memory error, a software glitch, or a progressively deteriorating circuit board within the controller.

• MX Magnum
• Case IH MX Magnum Series
• Case IH TG Series
• Case IH Steiger
• Case IH Puma

1. 1

   Locate the Remote Hydraulics (AUX) Controller on the back of the tractor and open the controller cover.

2. 2

   Turn the tractor's ignition key ON for more than two seconds, and then turn it OFF.

3. 3

   Listen closely or feel the controller for an internal relay 'click'.

4. 4

   Evaluate the click: If there is a click, the internal relay is working. If there is no click, the controller's internal hardware has failed.

5. 5

   Monitor for intermittent issues, which are likely caused by temperature changes acting on a progressively deteriorating controller board.

1. 1

   Perform the Relay Click Test

   Follow the diagnostic steps to check for an internal relay click.

2. 2

   Software Flash (If Relay Clicks)

   If the relay clicks but the 51109 code persists, the hardware may be intact but the software is corrupted. A dealer will need to connect the Case IH Electronic Service Tool (EST) to re-flash the controller software or clear the corrupted memory.

3. 3

   Replace the Controller (If No Click)

   If the relay does not click, the controller must be replaced.

4. 4

   Disconnect battery

   Disconnect the tractor's battery to prevent electrical spikes.

5. 5

   Unplug wiring harnesses

   Unplug the wiring harnesses from the faulty AUX controller.

6. 6

   Remove controller

   Unbolt and remove the controller from the rear of the tractor.

7. 7

   Install new controller

   Install the new Remote Hydraulics Controller and reconnect the harnesses.

8. 8

   Calibration

   A new controller will require dealer programming/calibration to communicate properly with the armrest and the tractor's CAN bus system.