Case IH 19647 – Engine Control Unit (ECU): Defect fault check for over temperature error

Internal diagnostic fault check indicating that a component, likely an internal power stage (driver circuit) within the control module, is reporting an over-temperature condition. This may be caused by excessive current draw from a shorted circuit.

• Tier 4b
• Case IH Tractors with Tier 4B SCR/DEF engines
• Case Construction Equipment N-Series Loaders (e.g., 580N)

1. 1

   Check for Short Circuits: Inspect the engine wiring harness for a short circuit to battery or short circuit to ground.

2. 2

   Inspect the DEF/AdBlue System Wiring: Inspect the wiring harness leading to the DEF tank module for chafing, melting, or pin corrosion.

3. 3

   Check ECU Power Stage: Verify if the ECU itself is excessively hot to the touch, which could indicate internal hardware failure.

1. 1

   Disconnect battery

   Disconnect the battery to prevent further damage to the ECU power stages.

2. 2

   Disconnect wiring harness

   Disconnect the main engine wiring harness from the ECU and the DEF/AdBlue tank level sensor.

3. 3

   Test harness for shorts

   Using a multimeter, perform a continuity and resistance check on the harness to check for shorts to ground or shorts to voltage.

4. 4

   Repair or replace wiring

   If a short is found in the harness, repair the damaged wiring or replace the engine wiring harness.

5. 5

   Replace ECU

   If the wiring tests good and the DEF sensor is not shorted, the over-temperature defect is likely an internal hardware failure within the ECU. The ECU will need to be replaced and flashed with the latest OEM software.

6. 6

   Clear codes and test

   Clear the fault codes and run the machine under load to verify the over-temperature error does not return.