Case IH 19359 – Engine Control Unit (ECU) / Engine Control Module (ECM): Downstream NOx Sensor could not perform self-diagnosis during after-run

The Downstream Nitrogen Oxide (NOx) sensor failed to complete its internal self-check during the engine's shutdown phase (the after-run sequence).

• Tier 4b
• Magnum 180
• Magnum 190
• Magnum 210
• Magnum 225
• Magnum 235
• Magnum 260
• Magnum 290
• Magnum 315
• Magnum 340
• Magnum 370
• Steiger 350
• Steiger 400
• Steiger 450
• Steiger 500
• Steiger 550
• Steiger 600
• Quadtrac 350
• Quadtrac 400
• Quadtrac 450
• Quadtrac 500
• Quadtrac 550
• Quadtrac 600
• Farmall 110A
• Farmall 120A
• Farmall 130A
• Farmall 140A
• Axial-Flow 5130
• Axial-Flow 6130
• Axial-Flow 7130
• Axial-Flow 7230
• Axial-Flow 8230
• Axial-Flow 9230
• Patriot Sprayer 2240
• Patriot Sprayer 2250
• Patriot Sprayer 3030
• Patriot Sprayer 3530
• Patriot Sprayer 4030
• Patriot Sprayer 4430
• Titan Floaters
• N-Series Tractor Loader Backhoes
• 521G
• 621G
• 821G
• 921G

1. 1

   Verify operator shutdown habits — ensure the battery master disconnect switch is not turned off immediately after shutting down the engine, as the ECU needs time to perform the after-run self-diagnosis.

2. 2

   Check for related battery voltage codes (19361 or 19362) which indicate the diagnosis was disabled due to abnormally high or low battery voltage.

3. 3

   Inspect the wiring harness and connector leading to the Downstream NOx Sensor for physical damage, melted wires, corrosion, or loose pins.

4. 4

   Check for exhaust leaks near the sensor mounting location, which can skew sensor readings.

5. 5

   Look for accompanying NOx sensor codes (e.g., 3521, 3528, 3529, 3530, 3532) which indicate a hard failure, open load, or short circuit within the sensor itself.

1. 1

   Ensure the machine's batteries are fully charged and the electrical system is providing the correct voltage.

2. 2

   Connect the Case IH Electronic Service Tool (EST) and clear the fault code.

3. 3

   Run the engine for a few minutes, then shut it down normally using the key switch.

   Do not turn off the battery master disconnect switch.

4. 4

   Wait for the complete after-run sequence to finish.

   You will typically hear the DEF pump purging.

5. 5

   Turn the key back on and re-check for fault codes.

6. 6

   If code 19359 returns and the wiring harness has been verified as intact, the Downstream NOx sensor has failed internally and must be replaced.

7. 7

   Remove the old sensor from the exhaust pipe and disconnect it from the harness.

8. 8

   Install the new NOx sensor.

   These are plug-and-play components.

9. 9

   Use the diagnostic tool to clear the error codes once more after fitting the new sensor.