Case IH 127 – TMF or AUX: Aux 2nd Lower Coil solenoid shorted to 12 volts

The control system has detected an electrical short to a 12-volt power source on the circuit responsible for actuating the "lower" directional solenoid on the 2nd auxiliary remote hydraulic valve.

• Magnum
• Case IH MX Magnum Series
• Case IH TG Series
• Case IH Puma Series
• Case IH Maxxum / MX Series
• Case IH STX Steiger Series

1. 1

   Inspect the wiring harness leading to the rear auxiliary valve stack for chafed wire insulation, melted loom, or pinch points where the solenoid signal wire might be shorting to a 12V power wire.

2. 2

   Disconnect the electrical plug at the 2nd Aux Lower solenoid and inspect the pins for corrosion, water ingress, or bent pins bridging the power and ground/signal circuits.

3. 3

   With the key ON and the solenoid unplugged, use a multimeter to check the signal wire on the harness side. If it reads a constant 12 volts without the remote lever being activated, the short is in the wiring harness or the controller.

4. 4

   Measure the resistance (Ohms) across the pins of the solenoid coil itself. If the resistance is near zero, the coil has failed internally (shorted) and must be replaced.

1. 1

   Safety First

   Turn off the tractor, relieve all hydraulic system pressure, and disconnect the negative battery cable.

2. 2

   Locate the Valve

   Locate the auxiliary remote valve block (typically at the rear of the tractor). Identify the 2nd remote valve section.

3. 3

   Identify the Coil

   Locate the specific solenoid coil controlling the "Lower" function on that valve section.

4. 4

   Disconnect

   Unplug the electrical connector from the faulty solenoid.

5. 5

   Remove the Coil

   Remove the retaining nut or clip at the end of the valve stem that holds the solenoid coil in place.

6. 6

   Swap Parts

   Slide the old coil off the proportional valve cartridge stem. Slide the new OEM replacement coil onto the stem.

7. 7

   Reassemble

   Reinstall the retaining nut (do not overtighten, as this can distort the coil or stem) and plug the electrical connector back in.

8. 8

   Test

   Reconnect the battery, clear the stored fault codes via the tractor's diagnostic display, and cycle the 2nd remote valve to verify proper raise/lower operation.