Case IH 12054 - EPL – EPL (Electronic Park Lock) Control Unit: Fault on power supply voltage reading

The control module is detecting that the incoming power supply voltage is outside of the specified operating range, or it has registered a sudden voltage spike.

• VESTRUM CVX
• Case IH Puma Series
• Case IH Steiger Series
• Case IH Magnum Series

1. 1

   Test the battery voltage and alternator output to ensure the vehicle's charging system is stable and not producing voltage spikes or operating out of range

2. 2

   Check the power supply voltage directly at the EPL module by testing pins A4 and C7 for proper voltage

3. 3

   Inspect the wiring harness and connectors leading to the EPL module for any short circuits to power or ground, particularly at pins A4 and C7

4. 4

   Use a voltmeter or the tractor's diagnostic display to monitor for sudden changes or drops in voltage values while operating to help isolate intermittent wiring faults

1. 1

   Address Charging Issues

   If the alternator is overcharging or the battery is failing, replace the faulty charging system component to eliminate voltage spikes.

2. 2

   Repair Wiring

   If testing reveals a short circuit or damaged wiring at pins A4 or C7 of the EPL module, repair or replace the affected section of the wiring harness. Clean and secure all ground connections.

3. 3

   Replace the EPL Module

   If the power supply, battery, and wiring are verified to be correct and stable, but the 12054 code persists, the EPL Control Unit itself has likely suffered internal damage from a spike and must be replaced.

4. 4

   Calibrate the EPL System

   After repairing the wiring or replacing the module, clear the fault codes. You must then perform the EPL calibration procedure. This involves using the 'h' and 'm' buttons on the control panel to calibrate the 'applied' and 'released' positions of the electronic park lock.