Case IH 1105 – ATC (Armrest/Cab Controller) / Transmission Controller: 12VU2 voltage supply to the EDC Top/Side Link load compensation is low. (possible blown fuse*)(CCH Only)

This code indicates that the 12-volt power supply circuit (designated as 12VU2) providing power to the Electronic Draft Control (EDC) Top/Side Link load compensation system has dropped below the acceptable voltage threshold. The system explicitly flags this as a likely blown fuse or an open circuit in the power supply line.

• Magnum
• Case IH Magnum Series 4 (Models 235, 260, 290, 315, 340)

1. 1

   Locate the fuse panel and test the fuse assigned to the 12VU2 EDC Top/Side Link circuit

2. 2

   Use a multimeter to measure the voltage at the 12VU2 supply pin on the EDC Top/Side Link load compensation connector (should read ~12V)

3. 3

   Inspect the wiring running to the EDC Top/Side Link for chafing, pinch points, or exposed wires that could be shorting to the tractor chassis (ground)

4. 4

   Disconnect the EDC Top/Side Link load compensation sensor/actuator and check for internal short circuits using a multimeter

1. 1

   Power Down

   Turn off the tractor, remove the key, and turn off the battery disconnect switch to ensure the electrical system is safe to work on.

2. 2

   Locate and Replace the Fuse

   Access the tractor's fuse block. Locate the specific fuse for the 12VU2 / EDC Top/Side Link circuit (refer to the fuse decal on the panel door). If the fuse is blown, replace it with a new fuse of the exact same amperage rating.

3. 3

   Trace the Short (If Fuse Blows Again)

   If the new fuse blows immediately upon key-on, there is an active short to ground. Disconnect the EDC Top/Side Link load compensation component.

4. 4

   Repair Wiring

   Trace the 12VU2 wire back to the cab controller. Repair any damaged, rubbed, or melted sections of the wiring harness using weather-sealed heat shrink connectors.

5. 5

   Replace Component (If Necessary)

   If the wiring harness tests perfectly fine (no shorts to ground) but the fuse continues to blow when the EDC Top/Side Link is plugged in, the component itself has failed internally and must be replaced.

6. 6

   Clear Codes and Calibrate

   Reconnect battery power, turn the key on, and use the Pro 700/1200 display or a diagnostic tool to clear the 1105 fault code. Test the hitch/EDC system to ensure the code does not return.