Case IH 519014-06 - UCM – UCM: Front suspension lock solenoid current high

The controller has detected an abnormally high electrical current draw on the circuit that controls the front suspension lockout solenoid. This typically indicates a short circuit to ground in the wiring harness, an internal short within the solenoid coil itself, or a failure within the control module.

• MAGNUM AFS Connect
• Magnum 180 AFS Connect
• Magnum 200 AFS Connect
• Magnum 220 AFS Connect
• Magnum 240 AFS Connect
• Magnum 250 AFS Connect
• Magnum 280 AFS Connect
• Magnum 310 AFS Connect
• Magnum 340 AFS Connect
• Magnum 380 AFS Connect
• Magnum 400 AFS Connect

1. 1

   Check for associated UCM voltage supply codes (e.g., 12V power supply low) which could indicate a blown fuse caused by a short circuit.

2. 2

   Locate the front suspension lockout solenoid valve on the suspension manifold block near the large accumulators under the front weight bracket. Visually inspect the wiring harness routing from the UCM to the solenoid. Pay special attention to areas near the bottom of the fan shroud and chassis pinch points, as harness rubbing and damage are common causes for shorts in this circuit.

3. 3

   Disconnect the electrical connector at the lockout solenoid and measure the resistance across the solenoid coil pins. Near zero resistance indicates an internal short.

4. 4

   With the solenoid disconnected, check the signal wire for a short to ground.

5. 5

   If the wiring harness and solenoid test within normal parameters, verify the UCM for an internal fault causing the high current reading.

1. 1

   Preparation

   Park the tractor on a level surface, lower any implements, turn off the engine, and disconnect the battery to prevent electrical spikes.

2. 2

   Locate the Solenoid

   Access the front suspension valve block located near the front accumulators.

3. 3

   Wiring Repair

   If the diagnostic inspection revealed chafed wires (e.g., near the fan shroud), cut out the damaged section, solder in new wire, seal with dual-wall heat shrink, and reroute/secure the harness away from vibration points.

4. 4

   Solenoid Replacement

   Disconnect the wiring harness connector from the lockout solenoid. Remove the retaining nut or clip holding the solenoid coil to the valve cartridge stem. Slide the old solenoid coil off the valve stem. (Note: You usually do not need to open the hydraulic system to replace just the electrical coil). Slide the new solenoid coil onto the stem and secure it with the retaining nut/clip.

5. 5

   Reassembly

   Reconnect the electrical connector to the new solenoid.

6. 6

   Calibration & Testing

   Reconnect the battery and power on the tractor. Clear the inactive fault codes from the UCM. Run a front suspension calibration cycle (Terraglide calibration) if required by the display, and test the suspension lockout function to ensure the code does not return.