Case IH 12172 – Universal Controller: Actuator - Cable disconnection

This code indicates that the control module has detected an open circuit or a complete disconnection in the wiring leading to the Electronic Park Lock (EPL) actuator.

• Puma/Mid Range Magnum
• MAXXUM T4E
• Case IH Puma series (140, 165, 180, 185, 195, 210, 225, 230)
• Case IH Magnum series (MX210, MX230, MX255, MX285)
• Case IH Maxxum series

1. 1

   Inspect the wiring harness running from the Universal Controller to the EPL actuator for obvious breaks, chafing, or rodent damage

2. 2

   Disconnect the EPL actuator and inspect the pins for corrosion, moisture, or pushed-out terminals (pay special attention to relay X036, switch connector X121, and EPL connector X745)

3. 3

   Use a multimeter to check the continuity of the wiring harness between the controller and the actuator

4. 4

   Measure the internal resistance of the EPL actuator itself to check for an internal open circuit (infinite resistance indicates a failed internal motor/solenoid)

1. 1

   Secure the Tractor

   Ensure the tractor is on level ground and securely chocked, as you will be working on the parking brake system.

2. 2

   Repair Wiring

   If the diagnostic checks revealed a broken wire or corroded connector, repair the harness or replace the connector pigtail. Clear the code and test the system.

3. 3

   Replace the Actuator

   If the wiring is intact but the actuator has an internal open circuit, remove the defective EPL actuator assembly from the transmission housing and install the replacement unit.

4. 4

   System Calibration

   After replacing the EPL actuator, you must re-calibrate the Electronic Park Lock system. This is done by accessing the 'H' menu diagnostics on the tractor's display (specifically the H1 - Calibration procedures menu for the EPL controller) or by using the dealer Electronic Service Tool (EST).

5. 5

   Verify

   Operate the system and check that the park lock engages/disengages smoothly and that code 12172 does not return.