Case IH 519010-03 - UCM – UCM: Front suspension center position sensor voltage high

The control module is receiving a voltage signal from the front axle suspension position sensor that exceeds the normal operating parameters. A "voltage high" condition typically points to an open circuit (such as a broken ground wire), a short to a power source in the wiring harness, or an internal failure of the sensor itself.

• MAGNUM AFS Connect
• Magnum 215
• Magnum 235
• Magnum 245
• Magnum 250
• Magnum 260
• Magnum 275
• Magnum 280
• Magnum 290
• Magnum 305
• Magnum 310
• Magnum 315
• Magnum 340
• Magnum 370
• Magnum 380

1. 1

   Inspect the wiring harness leading down to the front axle position sensor for chafed wires, cuts, or mud/debris buildup that could cause a short to power or an open circuit.

2. 2

   Disconnect the sensor and inspect the electrical connector pins for moisture, corrosion, or bent pins.

3. 3

   Access the tractor's diagnostic menu (often found in the 'Trans FSUS' menu on the A-post display) to monitor the live voltage/position readings of the sensor. If the voltage is stuck high regardless of axle movement, the sensor or its wiring is faulty.

4. 4

   Verify that the sensor's physical mounting and linkage on the front axle haven't been bent or damaged by field debris.

1. 1

   Preparation

   Safely park the tractor on level ground and fully lower the front suspension.

2. 2

   Removal

   Locate the front suspension position sensor on the front axle assembly. Disconnect the electrical connector.

3. 3

   Dismounting

   Unscrew the sensor cover attachment bolts and the sensor support screws to remove the assembly.

4. 4

   Marking

   Before completely removing the old linkage/bushings, mark the position of the ring holder bush to ensure you correctly position the rubber ring and linkage in its housing during reassembly.

5. 5

   Installation

   Install the new sensor, aligning it with the marks previously made. Tighten the mounting screws and reconnect the electrical connector.

6. 6

   Calibration

   After replacing the sensor, a suspended front axle calibration must be performed via the tractor's monitor. Note: For the calibration to initiate and complete successfully, the suspension must be fully lowered, and the system pressure sensors must be reading 0 psi at the start of the process.