Case IH 51509 – AUX67 / AUX89: Auto mode status lamp has an open circuit or is shorted to ground

The controller is trying to send a signal to illuminate the indicator lamp that shows a remote valve is in 'Auto' mode, but the electrical circuit is incomplete (open) or the voltage is being routed directly to the chassis ground (shorted).

• STX Steiger
• Steiger
• Magnum
• Puma

1. 1

   Inspect the remote valve control pod/armrest console where the Auto mode status lamp is located for physical damage to the switch or indicator.

2. 2

   Trace the wiring harness from the AUX67 or AUX89 controller to the status lamp, looking for pinched wires, chafing against the cab frame, or melted insulation.

3. 3

   Disconnect the harness at the status lamp and the controller and inspect the pins for corrosion, moisture, or pushed-back terminals.

4. 4

   Measure continuity from the controller pin to the lamp connector pin to test for an open circuit.

5. 5

   Measure continuity between the lamp power supply wire and a known good chassis ground to test for a short to ground (there should be no continuity).

6. 6

   If the wiring is intact, test the status lamp/LED itself to see if the internal filament or diode has failed open or shorted.

1. 1

   Power Down

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

2. 2

   Access the Component

   Remove the trim panels on the right-hand armrest console or the specific remote valve control pod to access the wiring for the 6th/7th or 8th/9th remote levers.

3. 3

   Isolate the Fault

   Based on your multimeter tests, determine if the fault is in the wiring harness or the lamp itself.

4. 4

   Repair Wiring

   If a wire is broken or shorted to the chassis, splice and solder a new section of wire, sealing it with heat-shrink tubing.

5. 5

   Replace the Lamp/Switch

   If the lamp is internally shorted or open, remove the retaining clips or screws holding the indicator/switch assembly in place and install the replacement unit. (Note: On many modern Case IH armrests, the status LED is integrated into the remote valve paddle/lever assembly or the circuit board).

6. 6

   Reassembly

   Reconnect all harness plugs and reinstall the armrest trim panels.

7. 7

   Clear Codes and Test

   Reconnect the battery, turn the key to the ON position, and clear the stored AUX67/AUX89 fault codes. Engage the remote valve into Auto mode to verify the lamp illuminates and the code does not return.