Case IH 520195-00 - VCM – UCM / VCM: Device temperature high

The internal temperature of the control module has exceeded its safe operating threshold. This can be caused by an internal hardware short, excessive current draw from a shorted external circuit, or extreme external environmental heat.

• MAGNUM 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
• Steiger AFS Connect Series

1. 1

   Connect the Case IH Electronic Service Tool (EST) to the CAN1/ISOBUS diagnostic connector and monitor the live internal temperature parameter of the UCM/VCM to verify if the sensor is reading accurately or defaulting to an extreme value.

2. 2

   Inspect the physical location of the UCM/VCM. Check for missing heat shields, proximity to unshielded exhaust/engine components, or heavy debris/dirt buildup that could be insulating the module and preventing heat dissipation.

3. 3

   Inspect the wiring harness and connectors (specifically the unswitched power, switched power, and ground pins) for signs of melting, corrosion, or short circuits.

4. 4

   Ensure the alternator is not overcharging, as excessive system voltage can cause control modules to overheat.

1. 1

   Safely Park the Machine

   Park the tractor on a level surface, turn off the engine, and disconnect the negative battery cable.

2. 2

   Expose the Module

   Locate the UCM/VCM and remove any interior cab trim or access panels required to reach it.

3. 3

   Disconnect Harnesses

   Carefully unplug the CAN bus and power connectors from the module (e.g., CN1-A, CN1-B). Inspect the pins on both the harness and the module for heat damage.

4. 4

   Replace the Module

   If the wiring and environment are normal but the module is overheating (or falsely reporting an overheat condition due to a failed internal thermistor), unbolt the defective UCM/VCM and install the replacement unit.

5. 5

   Reconnect and Power Up

   Reconnect the wiring harnesses and the battery.

6. 6

   Module Configuration

   Connect the EST to the diagnostic connector. Navigate to the toolbar, select Configuration, and then General Configuration. Program the new UCM/VCM with the correct software and parameters for the specific tractor (e.g., pump size, hitch options).

7. 7

   Calibration

   Because the UCM handles steering logic, you must perform a calibration of the Wheel Angle Sensor (WAS) after replacing the module.

8. 8

   Clear Codes

   Clear the active 520195-00 fault code and test-run the machine to ensure the temperature remains in the normal range.