Case IH 19053 (F-3222-12) – Engine Control Unit (ECU): Upstream NOx sensor internal failure (Heater Performance Plausibility Error)

This fault code indicates a malfunction within the internal heating circuit of the upstream Nitrogen Oxide (NOx) sensor. The control module has detected that the heater is not performing as expected—it may be heating up too slowly, drawing an incorrect amount of current, or experiencing an internal short/open circuit.

• VESTRUM CVX
• Magnum 180
• Magnum 200
• Magnum 220
• Magnum 240
• Magnum 250
• Magnum 280
• Magnum 310
• Magnum 340
• Puma 150
• Puma 165
• Puma CVT
• Steiger 580
• Farmall 40
• Farmall 45
• Farmall 50
• Farmall 115U
• Axial-Flow 5140
• Axial-Flow 6140
• Axial-Flow 7140
• Axial-Flow 7240
• Axial-Flow 8240
• Axial-Flow 9240
• Patriot 2250
• Patriot 3240
• Patriot 3340
• Patriot 4440
• Titan 3040
• Titan 3540
• Titan 4040
• Titan 4540
• Austoft 9900

1. 1

   Inspect the wiring harness and connector (e.g., C186) leading to the upstream NOx sensor for chafed wires, melted insulation, or bent/corroded pins

2. 2

   Verify that the sensor is receiving proper supply voltage (12V or 24V, depending on the machine) and has a solid ground connection

3. 3

   Ensure the CAN bus lines to the sensor are intact, as the sensor communicates data and heater status to the ECU via the CAN network

4. 4

   Inspect the exhaust piping upstream of the Diesel Oxidation Catalyst (DOC) for leaks, which can skew temperature readings and affect sensor plausibility

1. 1

   Preparation

   Turn off the engine, remove the key, and disconnect the machine's battery to prevent electrical shorts and ensure the exhaust system is cool to the touch.

2. 2

   Locate the Sensor

   Locate the upstream NOx sensor. It is positioned in the exhaust stream before the Diesel Oxidation Catalyst (DOC) and the Selective Catalytic Reduction (SCR) unit.

3. 3

   Disconnect

   Unplug the 5-pin electrical connector linking the NOx sensor to the machine's wiring harness.

4. 4

   Removal

   Using a specialized NOx/O2 sensor socket, carefully unscrew the faulty sensor from the exhaust pipe.

5. 5

   Installation

   Apply a high-temperature anti-seize compound to the threads of the new sensor (if it does not come pre-applied). Thread the new sensor into the exhaust pipe by hand to prevent cross-threading, then tighten to the OEM specified torque.

6. 6

   Reconnect

   Plug the sensor's electrical connector back into the harness, ensuring the locking tab clicks into place.

7. 7

   Clear Codes

   Reconnect the battery. Connect the Case IH Electronic Service Tool (EST) to the diagnostic port, clear the inactive 19053 (F-3222-12) fault code, and run the engine to verify the code does not return.