Case IH 19041 – Engine Control Unit (ECU): Upstream SCR temperature sensor comparison to a calculated temperature value failure.

This code indicates a plausibility failure. The control module calculates an expected exhaust temperature based on current engine load and operating conditions. If the physical reading from the upstream Selective Catalytic Reduction (SCR) temperature sensor deviates significantly from this calculated value, the system flags the sensor data as invalid or failed.

• Tier 4b
• 240 Series Axial-Flow Combines
• Farmall Tractors
• Puma Series Tractors
• N-Series Loaders

1. 1

   Use the electronic service tool (EST) to verify if the fault is currently active or stored.

2. 2

   Inspect the upstream SCR temperature sensor to ensure it is physically installed, correctly mounted, and not loose in the exhaust pipe.

3. 3

   Check the wiring harness and 2-pin connector for shorts, opens, or damage (Pin 1: 5-volt supply, Pin 2: Common ground to the ECU).

4. 4

   Look for other active exhaust or emissions-related fault codes (such as DOC temperature or NOx sensor faults) that might be causing an actual abnormal exhaust temperature rather than a sensor failure.

1. 1

   Cool Down

   Turn off the machine and allow the exhaust system to cool completely. The SCR system operates at extremely high temperatures and poses a severe burn risk.

2. 2

   Locate the Sensor

   Locate the upstream SCR temperature sensor on the exhaust piping. It is positioned just before the SCR catalyst chamber (downstream of the Diesel Oxidation Catalyst / DOC).

3. 3

   Disconnect Wiring

   Carefully disconnect the 2-pin electrical connector from the sensor harness.

4. 4

   Remove the Sensor

   Use the appropriate wrench to unscrew and remove the faulty temperature sensor from the exhaust pipe boss.

5. 5

   Install New Sensor

   Thread the new upstream SCR temperature sensor into the exhaust pipe and tighten it to the OEM specified torque (do not over-tighten, as this can damage the closed-tip probe).

6. 6

   Reconnect

   Reconnect the 2-pin electrical connector, ensuring the locking tab clicks into place.

7. 7

   Clear Codes

   Turn the key ON and use the diagnostic service tool to clear fault code 19041.

8. 8

   Test Operation

   Start the engine and allow it to reach normal operating temperature to verify the code does not return and the SCR system doses correctly.