Case IH 19011 (F-4363-04) - ECU – DCU / ECU: Downstream SCR catalyst temperature sensor voltage is lower than expected

The control module is receiving a voltage signal from the downstream exhaust gas temperature sensor that falls below the acceptable operating threshold, indicating a potential short circuit, open circuit, or failed sensor.

• VESTRUM CVX
• Case IH Magnum 235 - 340 (Series 4)
• Case IH Steiger Series (350, 400, 450, 500, 550, 600 hp models)
• Case IH Farmall 40, 45, 50 (with Cab and CVT transmission)
• Case IH Axial-Flow 240 Series Combines

1. 1

   Visually inspect that the downstream and upstream temperature sensors are installed correctly

2. 2

   Inspect the muffler for physical damage and verify that the exhaust gas piping is mounted correctly without leaks

3. 3

   Inspect the wiring harness and connectors for the downstream temperature sensor for signs of damage, corrosion, or a short-to-ground

4. 4

   Perform a plausibility test using an Electronic Service Tool to monitor live voltage and temperature readings to confirm if the sensor is drifting or completely dead

1. 1

   Ensure the machine is turned off and the exhaust system has completely cooled down to prevent burns.

2. 2

   Locate the downstream SCR catalyst temperature sensor (positioned in the exhaust tube after the SCR catalyst).

3. 3

   Disconnect the electrical connector for the sensor and inspect the pins. If the wiring harness is damaged, repair the harness.

4. 4

   If the wiring is intact but the sensor failed the plausibility test (or is reading out of range/shorted), remove the defective temperature sensor from the exhaust piping.

5. 5

   Install the new downstream SCR catalyst temperature sensor and tighten to OEM specifications.

6. 6

   Reconnect the electrical harness.

7. 7

   Connect the Electronic Service Tool. Clear the fault codes and, if required by the specific engine software, flash the new dataset or run a system test to reactivate the SCR system and verify the repair.