Case IH 12013 – Electronic Park Lock (EPL): Power stage – PH_A or PH_B short circuit to ground

The controller has detected that the electrical current for Phase A or Phase B of the actuator motor is finding a direct path to the chassis ground, bypassing the normal circuit load. This prevents the electric motor from operating correctly.

• Puma/Mid Range Magnum
• MAXXUM T4E
• Puma Series (140, 160, 165, 175, 180, 185, 195, 200, 210, 215, 225, 240 CVX / CVXDrive)
• Magnum Series (180, 210, 225, 255, 310)
• Maxxum Series (100-140)

1. 1

   Check active faults and calibration values in the tractor's diagnostic H menu (H1/H2) or Electronic Service Tool (EST).

2. 2

   Inspect the wiring harness between the EPL controller and the park lock actuator motor for rubbed, pinched, or melted wires causing a short to chassis ground.

3. 3

   Disconnect the EPL actuator and perform a motor continuity test using a multimeter to check for internal continuity between the motor pins and the motor housing (ground).

4. 4

   Check the mechanical condition of the parking brake assembly for binding, sticking, or warped brake rotors/steels on the input shaft.

1. 1

   Safety First

   Park the tractor on a level surface, heavily chock the wheels (since the park lock is malfunctioning), and disconnect the battery power.

2. 2

   Wiring Repair

   If the diagnostic checks revealed a chafed wire in the harness, repair the damaged section using appropriate weatherproof splices and heat shrink. Reroute and secure the harness to prevent future rubbing.

3. 3

   Actuator Replacement

   If the motor is internally shorted, locate the Electronic Park Lock actuator on the transmission housing. Disconnect the electrical connector, unbolt the actuator assembly, and install the replacement unit.

4. 4

   Mechanical Repair

   If the brake discs/rotors on the input shaft are warped or sticking (preventing the actuator from moving freely), the tractor may need to be split to access the transmission input shaft, clean the splines, and replace the brake pads and steels.

5. 5

   System Calibration

   After repairs are made and the battery is reconnected, you must recalibrate the Electronic Park Lock system using the Case IH Electronic Service Tool (EST) or via the onboard H1 calibration menu in the instrument cluster.