Case IH 19063 – Engine Control Module (ECM) / SCR Dosing Control Module: Upstream NOx sensor supply voltage is out of range

The electrical supply voltage traveling to the upstream Nitrogen Oxide (NOx) sensor is registering outside of the expected operating parameters (either too high or too low). This condition will often trigger a warning/fault light, an SCR failure warning, and can result in engine power loss or derating.

• Tier 4b
• 240 Series Axial-Flow Combines
• Farmall series (40, 45, 50, 110A, 120A, 130A, 140A, 115U)
• Puma series (150, 165, 185, 200, 220)
• Optum CVT series (270, 300)

1. 1

   Consult the specific FMI attached to the 19063 code to determine if the voltage is 'Above Normal' (short to high voltage) or 'Below Normal' (short to low/ground)

2. 2

   Inspect the physical wiring harness leading to the 5-pin upstream NOx sensor for severed lines, corrosion, or disconnected pins

3. 3

   If the machine has experienced full engine power loss, utilize the 'Emergency Re-start' function to safely move the machine into a diagnostic bay

1. 1

   Power down machine

   Power down the machine and disconnect the battery to safely service the emissions electrical system.

2. 2

   Locate sensor

   Locate the upstream NOx sensor in the exhaust system (before the SCR catalyst).

3. 3

   Repair wiring

   Repair any damaged wiring or short circuits in the harness leading to the sensor, as identified during the diagnostic phase.

4. 4

   Remove faulty sensor

   If the harness and supply voltage from the ECU are intact but the sensor's internal circuitry has failed (causing the out-of-range reading), remove the faulty upstream NOx sensor.

5. 5

   Install replacement sensor

   Install the replacement NOx sensor and reconnect the 5-pin connector.

6. 6

   Clear codes and test

   Clear the fault codes via the diagnostic display or service tool, and run the engine to ensure the SCR system builds pressure and the code does not return.