Case IH 626-03 - VCM – VCM: Vehicle controller drive enable voltage high

Voltage on the drive enable circuit is exceeding the maximum expected threshold. This typically points to a short to power in the wiring harness, a failed sensor/switch on the drive enable circuit, or an internal failure within the control module itself.

• MAGNUM AFS Connect
• Steiger
• Optum
• Puma

1. 1

   Inspect the VCM extension harness and the main chassis harness for chafing, pinched wires, or melted insulation that could cause the drive enable circuit to short to a 12V power source.

2. 2

   Disconnect the VCM connectors and check for bent pins, corrosion, or water ingress, which can bridge power pins to the drive enable pin.

3. 3

   Connect the Case IH Electronic Service Tool (EST) to monitor the live voltage data for the drive enable circuit. Toggle the drive enable switch/controls to see if the voltage state changes or remains stuck high.

4. 4

   With the battery disconnected, use a multimeter to test the drive enable circuit wire from the VCM to the transmission/drivetrain enable switch for a short to battery positive.

1. 1

   Repair Wiring

   If a short to power is found in the VCM extension harness or chassis harness, repair the damaged wire or replace the affected harness section.

2. 2

   Replace Switch/Sensor

   If the drive enable switch or interlock is internally shorted to power, replace the switch.

3. 3

   Replace the VCM

   If the wiring and inputs test good but the VCM still registers a high voltage on the drive enable circuit, the VCM has an internal fault and must be replaced.

4. 4

   Module Configuration

   If the VCM/UCM is replaced, you must use the Case IH Electronic Service Tool (EST) to flash the module and configure it to the tractor. The EST is required to set the configuration parameters so the tractor recognizes the new module and its associated systems.

5. 5

   Clear Codes

   Reconnect the battery, cycle the key, and use the EST to clear the 626-03 fault code. Perform a test drive to ensure the drive enable functions correctly and the code does not return.