Case IH 2655-06 - BCM – Body Control Module (BCM): Headlamp Low Beam Right #1 - Short circuit to ground

The electrical circuit supplying power to the right low beam headlamp has made contact with a ground source (such as the machine's chassis), causing the normal resistance to drop and grounding out the circuit. This typically causes the BCM to disable the circuit to prevent wiring damage or fire.

• MAGNUM AFS Connect
• Magnum Series (235-340)
• Magnum AFS Connect Series (180-380)
• Steiger AFS Series (CVT and Powershift)
• Optum AFS Series
• Farmall Series (Tier 4 / Tier 5 engines)

1. 1

   Consult the machine's electrical schematic to identify the exact routing of the right low beam circuit from the BCM to the headlamp

2. 2

   Inspect the wiring harness between the right headlamp and the BCM for chafing, pinched wires, or exposed copper touching the metal chassis (ground)

3. 3

   Disconnect the right headlamp assembly to see if the short circuit status changes to an open circuit (FMI 5), indicating the short is internal to the headlamp bulb or housing

4. 4

   With the headlamp disconnected, use a multimeter to measure resistance between the power supply pin on the harness connector and a known good chassis ground

5. 5

   Inspect the BCM connectors for water ingress, corrosion, or bent pins that could be bridging the headlamp power pin to a ground pin

1. 1

   Power Down

   Turn off the machine and disconnect the negative battery cable to prevent electrical arcing during repair.

2. 2

   Isolate the Short

   Based on the diagnostic checks, locate the exact point where the right low beam wire is contacting the chassis.

3. 3

   Repair the Harness

   If the wire is chafed, cut out the damaged section. Splice in a new section of wire of the same gauge using weather-sealed (heat-shrink) butt connectors. Wrap the repaired section in protective loom or electrical tape to prevent future chafing.

4. 4

   Replace Component

   If the short was isolated to the headlamp assembly itself, replace the right low beam bulb or the entire sealed headlamp unit.

5. 5

   BCM Replacement

   If the wiring harness tests perfectly clear of shorts, and the headlamp is good, the BCM may have an internal short on that driver circuit. The BCM will need to be replaced and reprogrammed.

6. 6

   Reassembly and Clearing

   Reconnect the battery. Use a diagnostic tool (such as Jaltest or MaxiSys CV) to clear the inactive 2655-06 fault code from the BCM. Turn on the headlamps to verify the right low beam illuminates and the code does not return.