Case IH 12 – TRANS: Master Clutch Potentiometer Short to +12 Volts or short to 5 Vreff

The system is detecting an abnormally high voltage signal from the clutch pedal position sensor, indicating that the sensor's signal circuit is shorted to a 12-volt power source or the 5-volt reference line.

• MX Magnum
• STX Steiger
• JXC
• Case IH MX Series
• Case IH TG Series
• Case IH Magnum 235 - 340 (Series 4)
• Case IH Puma

1. 1

   Connect a diagnostic service tool and monitor TRANS CLUTCH PEDAL POSITION PERCENT and TRANS CLUTCH PEDAL POSITION VOLTAGE

2. 2

   Perform a pedal sweep test to observe readings (should be 100% when fully released and 0% when fully depressed)

3. 3

   Inspect the wiring harness and connectors between the clutch pedal potentiometer and the transmission controller for rubbed, melted, or pinched wires

1. 1

   Disconnect

   Disconnect the battery to prevent electrical spikes.

2. 2

   Disconnect

   Disconnect the wiring harness at the master clutch potentiometer.

3. 3

   Test

   Using a multimeter, test the wiring harness for continuity to power (12V or 5V reference) on the signal circuit.

4. 4

   Repair

   If a short is found in the harness, repair or replace the damaged section of the wiring.

5. 5

   Replace

   If the wiring tests good, the short is likely internal to the sensor itself. Remove the faulty master clutch potentiometer and install a replacement.

6. 6

   Reconnect

   Reconnect the battery and the sensor harness.

7. 7

   Calibrate

   Perform a Pedal Calibration in the standard instrumentation or via the service tool so the transmission controller can learn the new sensor's physical end-stops.