Case IH 19776 – Engine Control Unit (ECU) or Dosing Control Unit (DCU): Counter for the DEF/AdBlue catalyst downstream Temperature monitoring.

The system detects an abnormal temperature reading (e.g., Signal Range Check high) from the catalyst temperature sensor located downstream of the Selective Catalytic Reduction (SCR) unit, indicating a defective sensor or a short circuit.

• Tier 4b
• Tier 4 Final
• Stage V
• Magnum
• Steiger
• Optum

1. 1

   Check the wiring harness connecting the downstream SCR temperature sensor to the ECU for any short circuits to an external power source or ground.

2. 2

   Verify the integrity of the electrical connectors for corrosion or backed-out pins.

3. 3

   Test the sensor itself for accuracy and proper resistance values.

1. 1

   Repair wiring

   Repair any identified wiring harness shorts.

2. 2

   Replace sensor

   If the wiring is intact, replace the defective SCR Catalyst Downstream Temperature Sensor.

3. 3

   Clear codes

   Clear the error codes from the ECU using a diagnostic tool (such as Jaltest or Case IH EST) and verify that the system communicates properly before returning the machine to service.