Case IH 2773 – Engine Control Module (ECM) or Electronic Park Lock (EPL) Controller: Post-Treatment NOx Output - Valid Data but Above Normal Operating Range - The Most Severe Level

Fault Code 2773 indicates the aftertreatment outlet NOx sensor is reading emissions levels exceeding the allowable threshold. The terminology 'EPL Recovery Status Forced Manual - Autoapply' refers to separate systems: Electronic Park Lock (EPL) automatic engagement and Forced Manual DPF regeneration.

• VESTRUM CVX
• Magnum
• Puma
• Maxxum
• Optum
• Case IH tractors and combines equipped with Tier 4 / Stage V Cummins/FPT engines

1. 1

   If diagnosing the 2773 NOx Code: Connect the Electronic Service Tool (EST) and verify if Code 2773 is active or inactive.

2. 2

   If diagnosing the 2773 NOx Code: Inspect the exhaust system and aftertreatment piping for leaks that could skew NOx sensor readings.

3. 3

   If diagnosing the 2773 NOx Code: Check the Diesel Exhaust Fluid (DEF) dosing unit and fluid quality, as poor DEF can cause high NOx output.

4. 4

   If diagnosing an EPL Autoapply / Recovery Issue: Check the tractor's battery voltage (dead batteries cause the EPL to fail to release).

5. 5

   If diagnosing an EPL Autoapply / Recovery Issue: Access the 'H' diagnostic menus (e.g., H2 or H3) on the instrument cluster to view stored EPL calibration values and check for specific EPL CAN faults (like 12146 or 14105).

1. 1

   Connect EST

   For the 2773 NOx Sensor Issue: Connect the EST to the diagnostic port.

2. 2

   Perform Forced Regeneration

   If soot/NOx levels are high due to incomplete regenerations, perform a Forced (Manual) Regeneration. Park the machine, set the throttle to low idle, and command the service regeneration via the EST or dashboard interface.

3. 3

   Replace NOx Sensor

   If the sensor data remains out of calibration after regeneration and DEF checks, replace the Post-Treatment NOx Sensor.

4. 4

   Clear Fault Codes

   Use the EST to clear the inactive fault codes and verify the repair.

5. 5

   Hold Brake Pedals

   For an EPL Reinitialization (If the park brake is stuck/auto-applied): Sit in the operator seat and hold down both brake pedals.

6. 6

   Release Hand Brake

   Release the hand brake.

7. 7

   Turn Ignition

   Turn the ignition key to the RUN position.

8. 8

   Shift to Neutral

   Place the shuttle/shift lever in the Neutral position.

9. 9

   Press Neutral Button

   Press the Neutral button on the shifter handle. The EPL should release and reinitialize.