Case IH 12943 – Transmission Control Module (TCM) / Vehicle Control Module (CVC): Service Brake Pedal Switch Circuit Fault

Voltage offset of Brake Pedal Sensor is detected, indicating the control module is reading an incorrect voltage offset from the brake pedal sensor or switch. This typically means the sensor's supply voltage is out of the expected range (Umin ~0.5 V to Umax ~4.5 V), or there is a physical circuit fault such as a short circuit, open wiring, or an insufficient power supply to the sensor.

• MAXXUM T4E
• Maxxum 110
• Maxxum 135
• MXM190
• Puma 165
• Optum 270 CVT
• Farmall 65C
• Farmall 75C
• Farmall 85C
• Farmall 95C
• Farmall 100C
• Farmall 105U
• Farmall 115U
• JX70
• JX90
• JX1070U
• JX1090U

1. 1

   Inspect mechanical linkage for dirt or debris under the brake pedal where it passes through the firewall, which can prevent the pedal from returning fully.

2. 2

   Perform a pedal travel test with the engine off by pushing and holding each brake pedal to ensure there is no mechanical binding.

3. 3

   Verify that the brake pedal switch is not out of physical adjustment.

4. 4

   Check the sensor supply voltage with a multimeter (limit values should be approximately 0.5 V to 4.5 V).

5. 5

   Test the brake pedal switch with a continuity meter to ensure it opens and closes correctly, and inspect the wiring harness for short circuits or open wiring.

1. 1

   Clean the Linkage

   Use a good light and compressed air to blow out any dirt or debris from the brake pedal linkage area at the firewall.

2. 2

   Adjust the Switch

   If the pedals move freely but the switch is not engaging, adjust the physical mounting position of the brake pedal switch so that it properly contacts the pedal arm.

3. 3

   Test the Circuit

   Disconnect the brake pedal sensor/switch harness. Probe the connector to verify that the module is sending the correct reference voltage (approx. 5V) and that the ground is solid.

4. 4

   Replace the Sensor/Switch

   If the switch fails the continuity test or the sensor has an internal voltage offset failure, remove the retaining hardware, unplug the electrical connector, and install a new OEM brake pedal switch/sensor.

5. 5

   Clear Codes and Calibrate

   Reconnect the battery/harness, clear the 12943 fault code from the TCM/CVC using a diagnostic tool, and test the brake pedals to ensure the code does not return and that functions like the differential lock and MFD engage properly.