Case IH 12 – Transmission ECM: CPDL_POT_HI_ERR - Clutch Pedal Potentiometer Signal Voltage Short to 5 or 12 Volts

The voltage at ECM connector 2, pin 24 goes above 0.96 volts either while the tractor is being driven or while it is in neutral, resulting in a disabling error that disables the power shuttle/clutch functions to protect the transmission.

• JXC
• Farmall series
• Maxxum
• Puma
• JX series
• TN Series (TN60A, TN70A, TN75A, TN85A, TN95A)
• T4000
• T6000
• T7000
• TM
• TSA series

1. 1

   Inspect the Wiring Harness: Check the wiring from the clutch pedal potentiometer to the Transmission ECM for any visible damage, rubbing, or pinched wires.

2. 2

   Test for Shorts: Using a multimeter, test the circuit at ECM connector 2, pin 24. You are looking for a short to a 5V or 12V power source.

3. 3

   Test the Sensor Supply: Verify the 5V sensor supply circuit and related fuses (e.g., Fuse 20) to ensure the reference voltage is correct and not shorted to battery voltage.

4. 4

   Test the Potentiometer: Sweep the clutch pedal while monitoring the sensor's resistance/voltage output. If the sensor has an internal short or reads out of bounds (above 0.96V at the bottom of the clutch stroke), the potentiometer itself has failed.

1. 1

   Disconnect Power

   Disconnect the tractor's battery before servicing the electrical system to prevent further shorts.

2. 2

   Locate the Sensor

   Locate the clutch pedal potentiometer, which is mounted directly on the clutch pedal assembly linkage.

3. 3

   Remove the Faulty Sensor

   Disconnect the electrical connector from the potentiometer. Remove the mounting hardware/safety pins securing the sensor to the pedal assembly.

4. 4

   Install the New Sensor

   Mount the replacement clutch pedal potentiometer and secure the hardware.

5. 5

   Reconnect

   Plug the electrical connector back into the sensor and reconnect the battery.

6. 6

   Calibrate the Transmission

   Because a new sensor has been installed, the Transmission ECM will not know the physical limits of the new potentiometer. You must perform a transmission clutch calibration procedure using the tractor's display or a diagnostic tool so the ECM can learn the new Bottom of Clutch (BOC = 0%) and Top of Clutch (TOC = 100%) voltage values.