Case IH 19360 (F-3224-12) - ECU – Engine Control Unit (ECU) or Aftertreatment Control Unit (A2CU+ / ACM): Upstream NOx Sensor Self-Diagnosis Failure

The Upstream NOx Sensor (located before the DOC) fails to perform its self-diagnosis during the engine's after-run phase, indicating an open circuit, a short circuit, or a CAN bus communication failure.

• VESTRUM CVX
• Magnum 180
• Magnum 200
• Magnum 220
• Magnum 240
• Magnum 250
• Magnum 280
• Magnum 310
• Magnum 340
• Puma 150
• Puma 165
• Steiger 580
• Quadtrac 620
• Combine 5140
• Combine 6140
• Combine 7140
• Combine 7240
• Combine 8240
• Combine 9240
• Patriot 2250
• Patriot 3240
• Patriot 3340
• Patriot 4440
• Titan 3040
• Titan 3540
• Titan 4040
• Titan 4540

1. 1

   Visually inspect the Upstream NOx sensor connector for moisture, dirt, corrosion, or pushed-out pins.

2. 2

   Verify that a 24V or 12V power supply is available to the sensor from the wiring harness (Pins 1 & 2 of the female connector).

3. 3

   Carry out a continuity check between the NOx sensor connector (Pins 1, 2, 3, 4, and 5) and the Aftertreatment Control Unit (A2CU+) connector (Pins 48, 55, 6, 1, and 16).

4. 4

   Ensure the CAN communication cables in the wiring harness are in order and check for any short circuits to the battery or ground.

1. 1

   Clean Connections

   If moisture or dirt is found in the connector, clean and dry the connector and pins. Reconnect and test to see if the code clears.

2. 2

   Repair Wiring

   If the wiring harness fails the continuity or short-circuit tests, repair or replace the defective wiring harness.

3. 3

   Replace Sensor

   If the wiring harness, power supply, and CAN communication lines are all in good working order, the Upstream NOx sensor has failed internally and must be replaced.

4. 4

   Clear Codes

   Install the new Upstream NOx sensor. Use a diagnostic tool to clear the fault codes and reset the engine restart / SCR validation counter to restore normal engine power and exit any derate conditions.