Case IH 520439-14 - BCM – BCM: Field light memory 2 recall switch - invalid input voltage

The control module is receiving a voltage signal from the Field Light Memory 2 Recall Switch that falls outside of the expected operating range. This is usually caused by a short to ground, a short to a 12V power source, an open circuit, or internal failure of the switch itself.

• MAGNUM AFS Connect
• Magnum 220
• Magnum 235-340

1. 1

   Visually inspect the Field Light Memory 2 Recall Switch on the control panel/armrest for physical damage or sticking buttons.

2. 2

   Disconnect the switch and inspect the 10-cavity electrical connector for moisture, corrosion, or pushed-back pins.

3. 3

   Use a multimeter to test the input voltage and ground at the switch harness. Verify that the reference voltage from the BCM is within the specified limits (typically 5V or 12V).

4. 4

   Test the continuity of the wires running from the switch connector back to the BCM to rule out an open circuit or a wire chafing against the chassis (short to ground).

5. 5

   Look for other active BCM fault codes. If multiple switch codes are present, it may indicate a shared ground failure or a broader BCM reference voltage issue rather than a single failed switch.

1. 1

   Power Down

   Turn off the tractor ignition and disconnect the negative battery cable to prevent electrical shorts during the repair.

2. 2

   Access the Switch

   Carefully remove the trim panel or armrest console housing the Field Light Memory 2 Recall Switch.

3. 3

   Disconnect the Harness

   Unplug the 10-cavity electrical connector from the back of the switch.

4. 4

   Replace Components

   If the wiring and connector are damaged, splice in a new connector and terminals. If the wiring tests good but the switch is outputting invalid voltage, remove the retaining clips/screws and replace the Field Light Memory Recall Switch.

5. 5

   Reassembly

   Plug the connector into the new switch and snap the console trim back into place.

6. 6

   Restore Power & Clear Codes

   Reconnect the battery. Turn the ignition to the Key ON, Engine OFF position. Use the Case IH Electronic Service Tool (EST) or the in-cab AFS Pro display diagnostic menu to clear the inactive DTCs from the BCM memory.

7. 7

   Functional Test

   Test the Field Light Memory 2 function to ensure the lights recall properly and the fault code does not return.