Case IH 153 – TRANS: Front Suspension pressure control not able to decrease pressure on the rod side.

The system is commanding the front suspension control valve to release or reduce hydraulic pressure on the rod side of the suspension cylinders, but the pressure sensor is not detecting the expected pressure drop.

• MX Magnum
• Case IH Magnum
• MX180
• MX285
• Magnum 215
• Magnum 245
• Magnum 275
• Magnum 305
• Magnum 335
• Magnum 340
• Magnum 380

1. 1

   Monitor live pressures by accessing the 'Trans FSUS' (Front Suspension) menu on the A-Post display to view the rod side (DA-R) and piston side (DA-K) pressure sensors.

2. 2

   Relieve pressure manually by turning the manual thumb screws down on the solenoids to lower the suspension and relieve all hydraulic pressure.

3. 3

   Verify sensor baseline once fully lowered. Both the rod side and piston side pressure sensors should read 0 psi (or ~30 kPa). If the rod side sensor still reads high, the sensor itself is likely failed or biased.

4. 4

   Check the suspension position potentiometer (located under the front left of the tractor) to ensure it is reading correctly, typically between 740mV and 1000mV depending on position.

5. 5

   Inspect the wiring harnesses and connectors at the suspended axle control valve block for shorts, corrosion, or open circuits.

1. 1

   Depressurize the System

   Park the tractor on a level surface. Lower the front suspension completely by turning the manual override thumb screws on the control valve solenoids to relieve all hydraulic pressure from the rod and piston sides.

2. 2

   Locate the Control Valve

   Locate the Suspended Axle Control Valve assembly on the front axle manifold.

3. 3

   Replace the Faulty Component

   If the diagnostic checks showed a biased pressure reading when depressurized, replace the Rod Side Pressure Sensor. If the sensor is reading accurately but the system physically cannot vent pressure, replace the Suspension Control Valve Solenoid / Cartridge Valve responsible for the rod side.

4. 4

   Re-engage Solenoids

   Screw the manual thumb screws back up to their operating positions.

5. 5

   Calibrate the Suspension

   Start the tractor and initiate the front suspension calibration procedure via the cab display. The system requires both pressure sensors to read 0 psi at the very start of the calibration sequence; otherwise, it will immediately fail the calibration and return a fault.