Case IH 12215 – Electronic Park Lock (EPL) controller or Universal Controller / XCM (Braking System): Factory – trailer relay present but not configured

The control module is detecting the physical electrical presence of a trailer brake relay on the circuit, but the software configuration within the controller is currently set to indicate that the tractor does not have a trailer brake relay installed.

• Puma/Mid Range Magnum
• MAXXUM T4E
• Case IH Puma series (165, 180, 195, 210, 225 CVX)
• Case IH Maxxum series
• Case IH Steiger series
• Case IH Farmall series
• Case IH Optum series

1. 1

   Inspect the tractor's electrical relay center to determine if a trailer brake relay is physically installed on the machine.

2. 2

   Access the tractor's diagnostic display and navigate to the EPL or Universal Controller to check the current software configuration for the trailer brake relay.

3. 3

   If the tractor is not equipped with a trailer brake relay, inspect the wiring harness and the empty relay socket for a short circuit to power or ground (which can trick the controller into detecting a relay).

1. 1

   Access the Diagnostic Menu

   Enter the tractor's on-board diagnostic system (the "H" menu) using the instrument cluster or armrest display.

2. 2

   Select the Controller

   Navigate to the Electronic Park Lock (EPL) controller (often designated as H1-H4 menus) or the Universal Controller.

3. 3

   Enter Configuration Mode

   Select the H3 menu (Configurations and options).

4. 4

   Update Configuration

   Locate the setting for the trailer brake relay. Change the configuration to match the physical hardware: Set to "Present" (or configured) if the relay is physically installed. Set to "Not Present" if the relay is not installed.

5. 5

   Repair Wiring (If Applicable)

   If the configuration was already correct but the code persists (and no relay is installed), locate and repair the short circuit in the trailer brake relay wiring harness.

6. 6

   Clear Fault Codes

   Once the configuration is updated or wiring is repaired, navigate to the HC menu (Clear all stored fault codes) or H8 menu to clear the stored error codes from the controller's EEPROM.

7. 7

   Cycle Power

   Turn the key off, wait for the controllers to power down, and restart the tractor to verify the code does not return.