Case IH 2380-03 - BCM – BCM: Trailer marker lamps - short circuit to B+

The system has detected a short circuit to B+ on the Trailer marker lamps circuit, meaning there is unwanted power (12V) on the circuit when it should not be, bypassing the normal switch or control circuit.

• MAGNUM AFS Connect
• Magnum
• Steiger
• Puma
• Maxxum
• Optum

1. 1

   Check the dashboard/display to see if any other error codes are present.

2. 2

   Disconnect the trailer from the tractor to determine if the short circuit is on the implement side or the tractor side.

3. 3

   Inspect the trailer connector pins and cavities for corrosion, which can cause electrical bridging.

4. 4

   Inspect the male connectors for bent, touching, or broken pins.

5. 5

   Use a multimeter to measure continuity and resistance on the trailer marker lamp circuit.

6. 6

   Test the circuit for unwanted voltage to verify if the line is receiving power when the lighting switch is turned off.

7. 7

   Verify that the tractor battery power supply has not been improperly connected to an external power supply.

1. 1

   Isolate the circuit

   Isolate the circuit by disconnecting the battery or ensuring the machine is powered down.

2. 2

   Inspect the wiring harness

   Inspect the tractor's trailer lighting wiring harness leading from the BCM to the rear 7-pin trailer connector. Look for chafed insulation, melted wires, or pinches where the marker lamp wire may be contacting a constant 12V power source.

3. 3

   Repair or replace damaged components

   Repair or replace any damaged sections of the wiring harness or the trailer connector socket.

4. 4

   Check the BCM

   If the wiring harness and connectors test good, the fault may lie internally within the BCM (hardware failure).

5. 5

   Clear the error code

   Once the wiring or component is repaired or replaced, clear the error code from the display.

6. 6

   Test the system

   Test the system for normal operation by turning on the marker lamps and verifying correct voltage and functionality.