Case IH 3509-05 - BCM – BCM (Body Control Module): Sensor regulated power (5V) - open circuit

The 5-volt reference circuit supplying power to one or more sensors has lost continuity or is completely open.

• 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

   Visual Inspection: Check the wiring harness originating from the BCM for any obvious signs of chafing, broken wires, or disconnected sensor plugs.

2. 2

   Continuity Testing: Use a multimeter to check for continuity on the 5V supply circuit between the BCM output pin and the connected sensors.

3. 3

   Voltage Check: Back-probe the BCM 5V output pin while the system is powered on to verify if the BCM is actually generating the 5-volt signal. If 5V is present at the BCM but not at the sensor, the harness is at fault. If 5V is not present at the BCM, the module itself may be faulty or require a software flash.

1. 1

   Disconnect Power

   Turn off the machine and disconnect the battery to prevent short circuits while working on the BCM harness.

2. 2

   Repair Wiring

   If the diagnostic checks revealed a broken wire or damaged connector on the 5V sensor circuit, splice and repair the wire using OEM-approved weather-sealed connectors, or replace the damaged sensor pigtail.

3. 3

   Reconnect and Clear Codes

   Reconnect the battery, power on the machine, and use the Case IH Electronic Service Tool (EST) to clear the 3509-05 fault code.

4. 4

   BCM Software Update or Replacement

   If the wiring is completely intact but the BCM fails to output the 5V reference, the BCM must be updated or replaced. Connect the EST and check the BCM software version. Service bulletins indicate that updating the BCM software resolves certain logic faults. If a hardware failure is confirmed, replace the BCM and flash it with the correct software payload for the specific tractor PIN.