Case IH 135 – TMF (Transmission/Multifunction Controller) or AUX (Auxiliary Valve Controller): Aux 4th Lower Coil solenoid shorted to 12 volts.

The electrical circuit controlling the lower (or retract) function of the 4th auxiliary hydraulic remote valve has an unintended short circuit to a 12-volt power source. The controller detects this abnormal voltage and disables the circuit to prevent damage.

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

1. 1

   Inspect the wiring harness leading to the 4th auxiliary remote valve block at the rear of the tractor for chafed wires, melted insulation, or pinched harnesses.

2. 2

   Disconnect the electrical connector at the 4th remote lower solenoid and check for water ingress, corrosion, or bent pins.

3. 3

   Use a multimeter to measure the resistance of the solenoid coil itself (a reading near zero ohms indicates an internal short).

4. 4

   With the solenoid disconnected and the key ON, probe the harness side of the connector. Reading 12 volts on the ground/control wire indicates a short in the wiring harness.

1. 1

   Power Down

   Turn off the tractor, remove the key, and disconnect the battery to protect the electrical system.

2. 2

   Locate the Component

   Locate the 4th auxiliary remote valve assembly at the rear hydraulic block. Identify the specific solenoid coil responsible for the 'lower' function.

3. 3

   Address Wiring

   If your diagnostic tests revealed a harness short, trace the wire back to the controller, locate the damaged section, and splice/repair the wire using weather-sealed connectors.

4. 4

   Replace the Solenoid Coil

   If internally shorted: Disconnect the electrical connector from the faulty solenoid. Remove the retaining nut or cap holding the solenoid coil to the hydraulic valve cartridge. Slide the old coil off the valve stem. Slide the new OEM replacement coil onto the stem and secure it with the retaining nut.

5. 5

   Reassemble and Test

   Reconnect the electrical connector and the battery.

6. 6

   Clear Codes

   Start the tractor and test the 4th remote valve operation. Clear the error codes from the multifunction controller display. If you are unable to clear the codes manually, a certified Case IH mechanic may need to clear them using the dealer diagnostic tool.