Case IH 2339 – Transmission Control Module / Universal Control Module (UCM): Creeper potentiometer - open circuit or short circuit to ground

The controller is receiving a voltage signal from the creeper position sensor that is either zero or below the minimum acceptable threshold. This typically indicates a broken wire, a disconnected harness plug, a short to ground in the wiring, or an internal failure of the potentiometer itself.

• Puma/Mid Range Magnum
• Case IH Puma series
• Case IH Magnum series (including MX/TG series)
• Case IH Maxxum series
• Case IH Steiger series

1. 1

   Check for secondary error codes (e.g., 2501, 2502, or 2552 related to transmission oil pressure). If present, diagnose and resolve those first as they may cause a cascading fault.

2. 2

   Inspect the wiring harness and connector at the creeper potentiometer for open circuits, corrosion, or wires shorting to the chassis ground.

3. 3

   Verify the mechanical creeper adjustment. Adjust the end-of-range bolts if necessary and attempt to re-perform the creeper calibration.

4. 4

   Inspect the synchronizer and its linkage for physical binding or damage.

1. 1

   Mechanical Repair

   If the synchronizer or its linkage is damaged or binding, repair or replace the mechanical components as required.

2. 2

   Replace Potentiometer

   If the creeper mechanicals and wiring harness are okay, remove the faulty creeper potentiometer and install a replacement.

3. 3

   Software Update

   If the fault is still present after replacing the sensor, connect your diagnostic tool and download/flash the correct level of software to the transmission controller.

4. 4

   Replace UCM

   If the fault recurs after a new sensor and software update, the internal driver in the controller has failed. Remove and replace the Universal Control Module (UCM).