Case IH 520595-04 - BCM – BCM: Voltage supply for processor - out of range - low

The control module has detected that the internal voltage being supplied to its microprocessor has dropped below the minimum acceptable operating threshold. This can be caused by a drop in the main vehicle power supply to the module, high resistance in the power/ground circuits, or an internal failure within the module's own power regulation circuitry.

• 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

   Verify that the tractor's batteries are fully charged and that the alternator is outputting the correct system voltage (typically ~14V while running)

2. 2

   Check all fuses and power relays that supply the BCM for blown fuses or high internal resistance

3. 3

   Inspect the main wiring harness connecting to the BCM for pushed-out pins, corrosion, or moisture intrusion

4. 4

   Perform a voltage drop test directly at the BCM's power supply pins while under load and compare to battery voltage to identify high resistance

5. 5

   Ensure the BCM ground connections are clean, tight, and free of paint or rust

1. 1

   Disconnect Power

   Turn off the battery disconnect switch to ensure safety before working on the electrical system.

2. 2

   Clean and Re-seat Connectors

   If the diagnostic checks reveal corrosion or loose connections at the BCM, clean the pins with electrical contact cleaner, apply dielectric grease, and securely reconnect the harness.

3. 3

   Repair Wiring (If Applicable)

   If a voltage drop was found in the harness, trace the circuit back to the power distribution center and repair the damaged wire or replace the faulty relay.

4. 4

   Replace the BCM

   If the external power and ground supplies to the BCM test perfectly within specification (approx. 12V) but the 520595-04 code remains active, the BCM's internal power supply has failed. The module must be replaced.

5. 5

   Module Programming

   Install the new BCM. A new BCM is blank and must be flashed/programmed using the Case IH EST (Electronic Service Tool) to match the tractor's specific PIN (Product Identification Number) and cab configuration.

6. 6

   Clear Codes

   Clear the inactive fault codes and cycle the key to verify the repair.