Case IH 519009-04 - UCM – UCM: Front suspension piston pressure sensor voltage low

The control module is detecting an abnormally low voltage signal from the piston-side pressure transducer on the front axle suspension system. This typically points to a short to ground in the wiring harness, moisture intrusion in the connector, or an internally failed pressure sensor.

• MAGNUM AFS Connect
• Case IH Magnum Series
• Case IH Puma Series
• Case IH Maxxum Series

1. 1

   Access the tractor's diagnostic display to view the live pressure readings (in kPa or mV) for the front suspension. Compare the piston-side pressure sensor reading against the rod-side pressure sensor reading.

2. 2

   Inspect the 3-pin electrical connector at the piston pressure sensor for moisture, dirt, or corrosion. Dampness inside the sensor connector is a known cause of erratic or out-of-range voltage readings.

3. 3

   Verify the wiring harness between the UCM and the sensor for continuity and ensure there is no short to ground.

1. 1

   Relieve System Pressure

   Turn the manual thumb screws down on the suspension valve block solenoids to lower the front suspension completely and relieve all hydraulic pressure from the system.

2. 2

   Disconnect the Sensor

   Unplug the 3-pin female electrical connector from the piston-side pressure sensor.

3. 3

   Remove and Replace

   Unscrew the faulty piston pressure transducer from the valve block and install the new replacement sensor.

4. 4

   Restore the System

   Screw the thumb screws on the solenoids back up to their operating position.

5. 5

   Calibrate

   Start the tractor and run the front suspension calibration cycle via the monitor to sync the new sensor and clear the fault codes.