Case IH 2338 – Central Controller (XCM / CCU) or Transmission Control Unit: Creeper potentiometer - short circuit to 8 volt or 12 volt

The signal voltage from the creeper gear position sensor is reading higher than the maximum allowed threshold, meaning the sensor has failed internally or the signal wire is shorted to a power source.

• Puma/Mid Range Magnum
• Puma Series 140, 150, 185, 200, 210, 220, 240
• Magnum Series 180, 210, 225, 250, 280, 310, MX210-MX285
• Maxxum & MXM Series 100-140, MXM120-MXM190
• Farmall Series (Models with CVT/Powershift)

1. 1

   Inspect the creeper synchronizer and its mechanical linkage for binding, bending, or physical damage

2. 2

   Enter the tractor's diagnostic/calibration menu (H-Menu or via the Electronic Service Tool - EST) and check the displayed potentiometer reading during calibration to see if the voltage is pegged high

3. 3

   Inspect the wiring harness connecting the creeper potentiometer to the controller for chafing or pinched wires that could cause a short to the 8V or 12V reference voltage

1. 1

   Repair Linkage

   If the synchronizer or its linkage is found to be damaged during the diagnostic check, repair or replace the mechanical components as required.

2. 2

   Replace Sensor

   If the creeper mechanicals and linkage are okay, remove and replace the creeper potentiometer.

3. 3

   Update Software

   If the fault is still present after replacing the potentiometer, connect the EST and download the correct/latest level of software to the controller.

4. 4

   Replace Controller

   If the fault recurs after a software update, the internal circuitry of the controller is likely shorted. Remove and replace the CCU (Central Control Unit).

5. 5

   Clear Codes & Calibrate

   Once repairs are made, clear the stored error codes (often via the HC menu) and perform a transmission/creeper calibration to learn the new sensor values.