Case IH 19474 – Engine Control Unit (ECU): Over temperature error of Exhaust flap powerstage

The Engine Control Unit (ECU) has detected an excessive temperature condition within its internal driver circuit (the "powerstage") that controls the exhaust flap actuator or relay. This is usually caused by excessive current draw, which can be the result of a short circuit to ground, a short circuit to battery, high resistance in the wiring, or a physically binding exhaust flap actuator.

• Tier 4b

1. 1

   Check the exhaust flap relay connector to ensure it is not loose or disconnected

2. 2

   Test the wiring harness between the ECU and the exhaust flap actuator/relay for a short circuit to the battery or a short circuit to ground

3. 3

   Check the exhaust flap actuator for increased electrical resistance or physical friction/binding

4. 4

   Check for abnormally high battery voltage or high ambient temperatures inside the ECU

1. 1

   Inspect Connections

   Locate the exhaust flap actuator and its corresponding relay. Disconnect and inspect the connectors for corrosion, pushed pins, or moisture. Reconnect securely.

2. 2

   Test the Harness

   Using a multimeter, check the continuity of the wiring harness from the ECU pins to the exhaust flap actuator. Verify there is no short to ground or short to voltage. Repair any damaged wiring.

3. 3

   Evaluate the Actuator

   Manually actuate the exhaust flap mechanism (if possible) to ensure it is not seized with soot or rust. If the flap is mechanically binding, clean or replace the mechanical flap assembly.

4. 4

   Test the Electrical Actuator/Relay

   If the wiring is intact and the flap moves freely, test the actuator motor and relay. If they are shorted internally, replace the exhaust flap actuator or relay.

5. 5

   ECU Replacement (Worst-Case)

   If the wiring, relay, and actuator are all functioning correctly but the error persists, the internal ECU powerstage has likely suffered permanent thermal damage. The ECU will need to be replaced or sent out for internal repair.