Case IH 2653-05 - BCM – Body Control Module (BCM): Headlamp Low Beam Left #1 - Current below normal or open circuit

The control module has commanded the left low beam headlamp to turn on, but it is detecting an 'under current' or 'open circuit' condition. The electrical path is broken, which is most commonly caused by a burnt-out headlamp bulb, a disconnected plug, or a severed wire in the left headlamp circuit.

• MAGNUM AFS Connect
• Case IH equipment
• Navistar/International trucks
• heavy-duty machinery

1. 1

   Inspect the left low beam headlamp bulb or sealed beam unit to see if the filament is broken or burnt out.

2. 2

   Disconnect the left headlamp harness connector and inspect the pins for corrosion, pushed-out pins, or moisture intrusion.

3. 3

   Turn the headlamp switch to the low beam position and use a multimeter to check for 12V (or 24V depending on the machine's system) at the power supply pin of the left headlamp connector.

4. 4

   Verify that the ground wire at the headlamp connector has continuity to the chassis ground.

5. 5

   If there is no voltage at the connector, trace the wiring harness back to the Body Control Module (BCM) to check for severed wires or chafing.

1. 1

   Power Down

   Turn off the machine and remove the key from the ignition to ensure the BCM is not actively sending power to the lighting circuits.

2. 2

   Access the Headlamp

   Remove any grilles, bezels, or retaining rings required to access the left front headlamp assembly.

3. 3

   Replace the Bulb/Assembly

   If the diagnostic checks revealed a burnt-out bulb (the most common cause of an open circuit), disconnect the wiring pigtail and replace the bulb or the entire sealed beam assembly. Do not touch the glass of a new halogen bulb with bare hands.

4. 4

   Repair Wiring (If Applicable)

   If the bulb was good but the harness was damaged, splice and heat-shrink the broken wire between the BCM and the headlamp, or replace the damaged connector pigtail.

5. 5

   Reassemble and Test

   Plug the connector back into the headlamp. Turn the ignition on and activate the low beams.

6. 6

   Clear Codes

   Verify the left low beam illuminates. The fault code should transition from 'Active' to 'Inactive' or 'Previously Active'. Clear the inactive code using an Electronic Service Tool (EST) if required.