Case IH 138 – TRANS (Transmission Controller): Front Suspension raise solenoid circuit shorted or open circuit.

The control module has detected an electrical fault—either a break in the wiring/coil (open circuit) or a short to ground/power (shorted circuit)—in the specific circuit that commands the solenoid responsible for raising the front axle suspension (often referred to as the Terraglide system).

• MX Magnum
• MX Magnum series (MX210, MX230, MX255, MX285)
• TG Series
• Steiger series (500, 550)
• Puma series

1. 1

   Inspect the wiring harness routed from the Transmission Controller to the front suspension control valve block for chafing, pinched wires, or melted insulation.

2. 2

   Disconnect the harness at the Front Suspension Raise Solenoid and check for water ingress, corrosion, or damaged/pushed-back pins.

3. 3

   Using a multimeter, measure the resistance across the pins of the raise solenoid coil to check for an internal failure (open circuit or dead short).

4. 4

   Disconnect the harness from the TRANS controller and the solenoid to test for continuity on the power and ground wires, and check for a short to ground or power.

1. 1

   Safety First

   Park the tractor on a level surface, engage the parking brake, and lower any implements. Crucial: Ensure the front suspension is fully lowered or mechanically supported. Working on the hydraulic valve block can cause the suspension to drop unexpectedly, creating a severe crush hazard.

2. 2

   Access the Valve Block

   Locate the front suspension control valve block (Terraglide manifold).

3. 3

   Repair Wiring

   If the diagnostic checks revealed a wiring issue, repair the broken wire or replace the damaged connector terminal using approved CNH electrical repair procedures.

4. 4

   Replace the Solenoid

   Disconnect the electrical connector from the raise solenoid. Remove the retaining nut holding the solenoid coil to the valve cartridge. Slide the old coil off. (Note: If the cartridge valve itself is sticking or leaking, the hydraulic system must be completely depressurized before unscrewing the cartridge from the block). Install the new solenoid coil and tighten the retaining nut. Reconnect the electrical harness.

5. 5

   System Calibration

   After repairing the circuit or replacing the solenoid, the front suspension system must be calibrated so the controller can relearn the raise and lower thresholds. Ensure the transmission oil is warmed to at least 60°C (140°F). Verify that the Standard Instrumentation (INST) and Armrest (ARM) controllers are already calibrated. Ensure no persons are in front of or behind the tractor. Enter the tractor's calibration menu and perform the front suspension auto-calibration procedure.