Case IH 299023-02 - VCM – VCM: Coil supply switch circuit fault

The control module has detected an electrical fault—such as an open circuit, short to ground, or short to power—in the circuit responsible for supplying voltage to a specific relay coil or solenoid switch.

• MAGNUM AFS Connect
• Magnum 400 AFS Connect

1. 1

   Check system voltage to verify that the battery voltage supplied to the VCM is sufficient (must consistently remain above 10.01V).

2. 2

   Inspect the fuses located directly on or adjacent to the Vehicle Control Module (VCM) for any blown fuses.

3. 3

   Visually inspect the wiring harness connecting the VCM to the relay/coil supply switch for chafing, corrosion, or loose connector pins.

4. 4

   Use a multimeter to check the coil supply circuit for continuity, open circuits, or shorts to ground/power between the VCM and the relay block.

1. 1

   Disconnect Power

   Turn off the machine and disconnect the battery to prevent further electrical damage while servicing the VCM circuits.

2. 2

   Locate Components

   Locate the Vehicle Control Module (VCM) and the main relay/fuse block.

3. 3

   Replace Fuses

   If any fuses on the VCM are blown, replace them with the correct amperage rating.

4. 4

   Repair Wiring

   If the diagnostic checks revealed an open or shorted wire in the harness, repair the damaged section of the wiring or replace the affected connector pins.

5. 5

   Replace Faulty Relay

   If the circuit wiring is intact but the relay coil itself is internally shorted or open (failing to switch the supply), replace the affected 12-volt power relay.

6. 6

   Reassemble and Clear Codes

   Reconnect the battery, turn the key on, and use the Case IH Electronic Service Tool (EST) to clear the fault code. Run the tractor to verify the code does not return.