Case IH 19067 (DTC 141A) - ECU – Engine Control Module (ECM): Downstream SCR catalyst temperature is too high.

This code indicates that the exhaust gas temperature sensor located downstream (after) the Selective Catalytic Reduction (SCR) catalyst is registering a temperature that exceeds the maximum safe operating threshold. This condition can trigger an engine power loss (derate) to protect the exhaust aftertreatment system from thermal damage.

• MAXXUM T4E
• 240 Series Axial-Flow Combines
• Maxxum (115-150)
• Puma (140-240)
• Farmall (90C-120U)
• Optum CVT series
• Patriot Sprayers (Tier 4)
• WD-series Windrowers (WD1204–WD2504)

1. 1

   Sensor Verification: Check the downstream exhaust gas temperature (EGT) sensor for physical damage, short circuits, or out-of-range resistance. A failed thermistor inside the sensor will often falsely report a 'too high' temperature.

2. 2

   Wiring & Harness Check: Inspect the wiring harness and connectors between the EGT sensor and the ECM for chafing, melting, or corrosion that could cause a short to a high-voltage source.

3. 3

   System Inspection: Check the SCR catalyst for face plugging or excessive soot/DEF buildup.

4. 4

   Dosing System Test: Verify the DEF dosing injector is not over-dosing or leaking. Unburnt hydrocarbons or excessive DEF reacting in the catalyst can cause genuine extreme temperature spikes.

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 downstream SCR temperature sensor on the exhaust pipe, positioned immediately after the SCR catalyst EGP (Exhaust Gas Processor).

3. 3

   Disconnect

   Disconnect the electrical harness connector from the sensor.

4. 4

   Remove the Sensor

   Use a wrench to carefully unscrew the faulty temperature sensor from the exhaust pipe. Note: Exhaust sensors frequently seize; apply penetrating oil and allow it to soak if the sensor is stuck.

5. 5

   Install the New Part

   Thread the new OEM temperature sensor into the exhaust pipe and tighten to the manufacturer's specified torque.

6. 6

   Reconnect

   Reconnect the electrical harness, ensuring the locking tab clicks into place and the wire is routed away from direct heat sources.

7. 7

   Clear Codes

   Use a diagnostic tool (such as the Case IH EST or KTS Truck scanner) to clear the fault code. Run the engine and perform a forced regeneration or SCR system test to verify the repair and ensure temperatures remain in the normal range.