Case IH 519012-05 - UCM – UCM: Front suspension piston control solenoid - Current Below Normal or Open Circuit

The control module is trying to send an electrical signal to the front suspension piston control solenoid, but it is detecting little to no current draw. This is almost always caused by a broken wire, an unplugged connector, or an internally failed (open) solenoid coil.

• MAGNUM AFS Connect
• Magnum 180
• Magnum 200
• Magnum 235
• Magnum 240
• Magnum 280
• Magnum 290
• Magnum 310
• Magnum 340
• Magnum 380
• Puma 130
• Puma 145
• Puma 150
• Puma 160
• Puma 165
• Puma 180
• Puma 195
• Puma 210
• Steiger 350
• Steiger 480
• Steiger 500
• Steiger 550
• Steiger 580
• Steiger 600
• Quadtrac 350
• Quadtrac 480
• Quadtrac 500
• Quadtrac 550
• Quadtrac 580
• Quadtrac 600
• Maxxum 100-140

1. 1

   Inspect the wiring harness routing from the UCM to the front suspension control valve block for chafed, pinched, or broken wires.

2. 2

   Disconnect the plug at the front suspension piston control solenoid and inspect the pins for corrosion, moisture ingress, or pushed-out terminals.

3. 3

   Using a multimeter, measure the resistance across the two pins of the solenoid coil to check for an internal open circuit (OL or infinite resistance).

4. 4

   If the coil tests good, perform a continuity test on the two wires running from the solenoid connector back to the UCM to pinpoint the open circuit.

1. 1

   Preparation

   Park the tractor on a level surface. If the suspension is currently raised, safely support the front chassis with heavy-duty stands, as working on the suspension valves can cause the tractor to drop unexpectedly. Turn off the engine and disconnect the battery.

2. 2

   Locate the Valve

   Locate the front suspension control valve block (often mounted near the front axle accumulators). Identify the specific piston control solenoid.

3. 3

   Harness Repair (If Applicable)

   If your diagnostics revealed a broken wire (commonly near the fan shroud or axle pivot), cut out the damaged section and repair it using weather-sealed, heat-shrink butt connectors. Secure the harness out of the way of moving parts.

4. 4

   Solenoid Replacement (If Applicable)

   Thoroughly clean the area around the valve block to prevent dirt from entering the hydraulic system. Disconnect the electrical connector. Remove the retaining nut holding the solenoid coil to the valve stem, and slide the old coil off. (If the entire cartridge valve needs replacing, unthread it from the block). Slide the new solenoid coil onto the stem and tighten the retaining nut to OEM torque specs.

5. 5

   Reassembly

   Reconnect the electrical plug and the battery.

6. 6

   Calibration

   Start the tractor and clear the UCM fault codes via the cab display. Test the suspension (raise/lower/lockout). Note: Depending on the model, replacing suspension hydraulic components may require you to run a front suspension travel range calibration via the AFS display.