Case IH 520568-06 - BCM – BCM: Door light auto driver - short circuit to ground

The system has detected that the electrical circuit responsible for automatically powering the cab door interior light is shorting directly to the chassis ground. This prevents the light from functioning and can blow a fuse or cause the module to disable the circuit to protect itself.

• 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

   Remove the cab door light lens and inspect the bulb and socket. A melted socket or a failed bulb can cause an internal short to ground.

2. 2

   Locate the cab door light push-button switch on the door jamb/pillar. Disconnect it and use a multimeter to check if the switch has failed internally, causing a permanent ground state.

3. 3

   Disconnect the harness at the BCM and at the door light. Use a multimeter to test the power supply wire for continuity to the cab frame (ground).

4. 4

   Trace the wiring harness from the door pillar up to the cab roof. Look for pinched wires, chafed insulation, or exposed copper touching the metal cab frame, particularly near the door hinges and roof paneling.

1. 1

   Disconnect Power

   Turn off the battery isolator switch to prevent electrical spikes while working on the BCM circuits.

2. 2

   Access the Components

   Remove the interior cab trim panels necessary to access the door light switch and the overhead dome/door light assembly.

3. 3

   Repair Wiring (If Applicable)

   If a chafed wire was found during the diagnostic phase, cut out the damaged section, solder in a new piece of wire, and seal it with heat-shrink tubing. Secure the harness away from pinch points.

4. 4

   Replace Faulty Components

   If the door switch is internally shorted, pop the old switch out of the pillar, plug the harness into the new switch, and snap it back into place. If the light socket is melted/shorted, splice in a new light assembly.

5. 5

   Reassemble and Clear Codes

   Reinstall all cab trim. Turn the battery isolator back on. Turn the ignition to the ON position and use the AFS Pro display or a diagnostic tool to clear the inactive BCM fault codes.

6. 6

   Verify Operation

   Open and close the cab door to ensure the auto door light turns on and off correctly without triggering the 520568-06 code.