Case IH 587-00 - VCM – VCM (Vehicle Control Module): VCM: Vehicle controller supply voltage low

This fault indicates that the system power supply voltage to the Vehicle Control Module (VCM) has dropped below the acceptable operational threshold.

• MAGNUM AFS Connect
• Skid Steer Loaders (SSL)
• Compact Track Loaders (CTL)
• Wheel Loaders
• Magnum/Puma series tractors

1. 1

   Verify the base battery or vehicle power supply voltage to ensure the machine is generating sufficient power.

2. 2

   Using a Digital Volt-Ohm Meter (DVOM), check for proper voltage (typically 12V) at the VCM power distribution panel and directly at the VCM harness connectors.

3. 3

   Inspect the fuses and wiring harnesses supplying the VCM for open circuits, corrosion, or high resistance.

1. 1

   Restore Base Voltage

   If the battery voltage is low, recharge or replace the battery and verify if the fault clears.

2. 2

   Repair Wiring/Connections

   If the DVOM shows less than the required voltage at the VCM but the battery is fully charged, trace the circuit back to the power distribution panel. Repair or replace any damaged wiring harnesses, corroded connectors, or blown fuses.

3. 3

   Replace the VCM

   If 12V is confirmed at the VCM connector but the module still logs a 'supply voltage low' fault, the VCM has likely suffered an internal failure and must be replaced.