Case IH 518109-06 - BCM – BCM: Short circuit to ground on the circuit powering Work Lamp #12

Fault code 518109-06 indicates a short circuit to ground on the circuit powering Work Lamp #12. The power supply wire leading to the work lamp has likely chafed and is touching the metal chassis (ground), or the lamp assembly itself has suffered an internal short. This condition causes a voltage drop to 0V and can trigger the module to disable the circuit to protect the system.

• MAGNUM AFS Connect
• Magnum 180
• Magnum 200
• Magnum 250
• Magnum 280
• Magnum 310
• Magnum 340
• Magnum 380 AFS Connect
• Steiger
• Puma
• Maxxum
• Axial-Flow 7250
• Axial-Flow 7260
• Axial-Flow 8250
• Axial-Flow 8260
• Axial-Flow 9250
• Axial-Flow 9260

1. 1

   Inspect the wiring harness leading to Work Lamp #12 for obvious signs of chafing, pinched wires, or melted insulation where the harness routes along the cab frame or fenders.

2. 2

   Disconnect the work lamp and inspect the connector pins for water intrusion, corrosion, or melting, which can bridge the power and ground pins.

3. 3

   With the machine off and the lamp disconnected, use a multimeter to perform a continuity test between the power supply wire in the harness and a known good chassis ground. Continuity indicates a harness short; no continuity indicates an internal lamp short.

1. 1

   Power Down

   Turn off the ignition switch and disconnect the battery to prevent electrical damage during testing.

2. 2

   Isolate the Fault

   Disconnect the electrical connector at Work Lamp #12.

3. 3

   Test the Harness

   Measure the resistance to ground on the harness side. If the harness is shorted to ground, trace the wire back toward the BCM. Locate the chafed section (often near pivot points or tight bends) and repair the wire using weather-sealed heat-shrink connectors.

4. 4

   Test the Lamp

   If the harness tests good, the work lamp has an internal short. Replace the work lamp assembly.

5. 5

   BCM Verification

   In rare cases where the harness and lamp are both fine, the BCM itself may have an internal short on that specific driver circuit. If so, the BCM will require replacement and reprogramming.

6. 6

   Clear Codes

   Reconnect the battery, turn on the work lights to verify operation, and use a diagnostic scan tool to clear the fault code from the BCM.