Case IH 519009-07 - UCM – UCM: Front suspension piston pressure not changing

The control module is commanding the front suspension to adjust, but the pressure sensor located on the piston side of the suspension cylinder is not registering any change in hydraulic pressure. This indicates that either the sensor has failed and is stuck at a static reading, there is a wiring interruption, or a hydraulic/mechanical issue is physically preventing the suspension from moving and building pressure.

• MAGNUM AFS Connect
• Case IH Magnum AFS Connect Series
• Magnum 280 AFS Connect
• Magnum 310 AFS Connect
• Magnum 340 AFS Connect
• Magnum 380 AFS Connect
• Magnum 400 AFS Connect
• Case IH Magnum models with Suspended Front Axle (SFA)
• Case IH Steiger models with Suspended Front Axle (SFA)

1. 1

   Verify Physical Movement: Command the suspension to raise or lower manually. If it moves but the code triggers, the sensor or wiring is likely the culprit. If it does not move, check for a hydraulic supply issue, stuck lock valve solenoid, or failed accumulator.

2. 2

   Check Sensor Readings: Use a diagnostic tool or AFS Pro 1200 monitor to view live data for Piston Side Pressure and Rod Side Pressure. If piston side pressure is stuck at a static value, the sensor is likely dead.

3. 3

   Inspect Wiring and Connectors: Check the wiring harness leading to the piston pressure sensor on the front axle block for rubbed wires, moisture intrusion, or bent pins.

4. 4

   Check Accumulator Charge: Verify the nitrogen charge in the accumulators matches the spec for your specific Magnum (typically around 856-899 PSI).

1. 1

   Relieve System Pressure

   Park the tractor on a flat, level surface. Lower the front suspension completely to relieve hydraulic pressure. Turn the manual thumb screws down on the suspension solenoids to bleed off the pressure.

2. 2

   Disconnect the Battery

   Turn off the master disconnect switch to prevent any electrical shorts while working on the UCM sensor network.

3. 3

   Remove the Sensor

   Locate the piston side pressure sensor on the front suspension hydraulic manifold block. Disconnect the electrical connector and unthread the sensor. Have a rag ready to catch residual hydraulic fluid.

4. 4

   Install the New Sensor

   Thread the new OEM pressure sensor into the manifold and tighten to the specified torque. Reconnect the wiring harness, ensuring the weather seal clicks into place.

5. 5

   Restore the System

   Turn the manual solenoid thumb screws back to their operating position and turn the battery power back on.

6. 6

   Perform Suspension Calibration

   Navigate to the calibration menu on the tractor's display to recalibrate the front suspension. The system will automatically raise and lower the tractor to learn the new sensor's voltage limits at the upper and lower suspension travel boundaries.