Case IH 47 – TRANS (Transmission Controller): Clutch pedal bottom of clutch switch misadjusted

This condition occurs when the transmission controller detects that the Bottom of Clutch (BOC) switch is out of sync with the clutch pedal position potentiometer, or the switch is engaging at the wrong point in the pedal's travel.

• MX Magnum
• STX Steiger
• JXC
• Magnum Series (MX series, Series 4 235–340)
• Steiger / Quadtrac Series (STX 450, 500, 350 Row Trac)
• Puma Series (Puma 155)
• TG Series

1. 1

   Monitor Pedal Position via Display: Enter the TRANS VIEW menu on the tractor's instrumentation controller or use an electronic service tool. Slowly cycle the inching (clutch) pedal. The display should read 100% when the clutch is fully up and 0% when fully depressed.

2. 2

   Test Switch Resistance: Disconnect the Bottom of Clutch switch and test it with a multimeter. When the switch is closed (pedal fully depressed), it should read approximately 4 ohms of resistance. If it reads excessively high, the switch has failed internally.

3. 3

   Inspect Mechanical Linkage: Check the clutch pedal potentiometer, the mechanical stop bolt, and the switch mounting bracket. Look for loose hardware or shifting caused by temperature changes.

4. 4

   Check Wiring: Inspect the electrical connector (C626) and harness for shorts, corrosion, or open circuits.

1. 1

   Replace Faulty Components

   If the BOC switch failed the resistance test or the linkage is damaged, replace the necessary parts.

2. 2

   Mechanical Adjustment

   Adjust the clutch pedal stop bolt and the Bottom of Clutch switch so the switch engages exactly at the bottom of the pedal's travel.

3. 3

   Potentiometer Fine-Tuning

   While watching the TRANS VIEW display, adjust the clutch position potentiometer. When the BOC relay clicks, the display should ideally read exactly 4% or 5%.

4. 4

   Electronic Calibration

   Once all mechanical components are tight and adjusted, you must perform the pedal calibration procedure. Navigate to TRANS SETUP on the instrumentation controller and run the clutch (inching) pedal calibration.

5. 5

   Arm the Transmission

   Cycle the clutch pedal fully to arm the transmission controller and clear the neutral/A:0 state.