Case IH 521-16 - ITBV – ITBV (Trailer Brake Control) module: Service Brake Pedal Switch Circuit Fault

The controller is detecting that the electrical signals from the left or right brake pedal switches are inconsistent, out of calibration, or physically implausible.

• MAGNUM AFS Connect
• AFS Connect Magnum 180
• AFS Connect Magnum 200
• AFS Connect Magnum 220
• AFS Connect Magnum 240
• AFS Connect Magnum 250
• AFS Connect Magnum 280
• AFS Connect Magnum 310
• AFS Connect Magnum 340
• AFS Connect Magnum 380
• Puma 150-200
• Puma 165
• Puma 200 CVT
• Optum 270 CVT
• Maxxum 110
• Maxxum 135
• Farmall 100C
• Farmall 105U
• Farmall 115U
• Farmall 120C

1. 1

   Verify if the brake pedal switch is mechanically misadjusted and broadcasting an implausible position signal.

2. 2

   Perform a switch function test to verify both left and right brake switches physically open and close when the pedal is depressed and released.

3. 3

   Check the right and left-hand brake switches for 12-volt power with the ignition ON to rule out a blown fuse or failed wire.

4. 4

   Ensure there are no underlying ITBV CAN communication errors (such as code 12586) preventing switch data from reaching the TECU.

1. 1

   Access the Switches

   Locate the brake pedal switches, typically found behind the kick panel directly above the brake pedal assembly.

2. 2

   Adjust or Replace

   If the switches are intact but misadjusted, realign them so the plunger fully depresses when the pedal is at rest. If the switch fails the open/close continuity test during diagnostics, remove the failed switch.

3. 3

   Wiring Repair (If Applicable)

   If the 12-volt power check failed, trace the wiring harness back to the fuse panel. Repair any broken wires or replace the blown fuse.

4. 4

   Install New Switch

   Install the replacement brake pedal switch and connect the 4-terminal harness.

5. 5

   Verify Repair

   Reconnect all connectors and ensure components are properly installed. Turn the key ON (engine off), connect your diagnostic tool (e.g., ServiceRanger or Case IH Electronic Service Tool), and clear all inactive faults. Operate the vehicle and depress the brake pedals to verify the fault code does not return.