Case IH 12133 – EPL (Electronic Park Lock) Controller: CAN Bus Mute EPL

Communication failure where the CAN (Controller Area Network) bus is "muted" or failing to receive/transmit messages properly to the Electronic Park Lock (EPL) system.

• Puma/Mid Range Magnum
• MAXXUM T4E
• Case IH Puma Series
• Case IH Magnum Series
• Case IH Maxxum Series
• Case IH Farmall

1. 1

   Access Diagnostic Mode by inserting the diagnostic test switch (Special Tool 380000843) into the main diagnostic connector located in the cab on the right-hand side rear pillar behind the operator's seat.

2. 2

   Navigate to the XA module, menu H2, and press the dimming key to check stored Electronic Park Lock calibration values.

3. 3

   Navigate to the HC menu and depress the dimming button to clear all stored fault codes without erasing calibration information, noting if code 12133 immediately returns.

4. 4

   Inspect the CAN bus wiring harness at the EPL controller, specifically checking the 24-pole FCI SICMA connector (X-700) for loose pins, corrosion, or damaged wires.

1. 1

   Reset EEPROM

   With the diagnostic switch installed, navigate to the H8 menu on the instrument cluster. This menu clears stored error codes and resets all EEPROM calibration values back to default (this is often required if the battery was disconnected or power was lost to the controller).

2. 2

   Recalibrate the EPL

   Use the 'h' and 'm' keys on the cluster to calibrate the applied and released positions of the park lock. Depress and hold the 'm' button to calibrate the released position. Wait for the lower central display to show 'donE'.

3. 3

   Replace the Controller

   If the CAN bus remains muted (code 12133 returns) and the actuator will not accept calibration, the EPL Controller Unit / Actuator has failed internally and must be replaced.

4. 4

   Re-test

   After installing a new EPL controller, repeat the H8 reset and calibration procedures.