Case IH F-3510-12 - ECU – Engine Control Unit (ECU) / Engine Control Module (ECM): ECU 5 volt sensor supply 2 out of range failure (ECU Power Stage 2: Error Sensor supply for sensors)

The Engine Control Unit (ECU) provides a regulated 5-volt reference signal to power a specific group of engine sensors (Sensor Supply Circuit 2). This code triggers when the ECU detects that the voltage on this circuit is outside of the normal operating range. It can be caused by an overvoltage (short to a higher voltage source like the 12V battery), an undervoltage (short to ground), an excessive electrical draw from a failed sensor, or an internal failure within the ECU's power stage.

• MAGNUM AFS Connect
• Case IH Magnum Series (Magnum 180 through 400, including AFS Connect, Tier 3, and Tier 4 models)
• Case IH Steiger / Quadtrac Series (Steiger 420, 470, 500, 540, 620, and STX models)
• Case IH Puma & Maxxum Series
• Skid Steers and Compact Track Loaders utilizing F5C or ISM-DI engines

1. 1

   Check Battery and Alternator Voltage: Ensure the tractor's base voltage is correct. Excessive battery voltage or a failing alternator can cause the ECU to register an overvoltage on the 5V circuit.

2. 2

   Isolate the Sensors: Disconnect sensors on the Supply 2 circuit (Fuel Filter Differential Pressure, Engine Oil Rifle Pressure, Water Pump Clutch, EGR Throttle position) one at a time. If the 5-volt reference returns to normal upon unplugging a specific sensor, that sensor is internally shorted.

3. 3

   Inspect the Wiring Harness: Check the engine wiring harness for chafing, melting, or pinches. Look for a short circuit to ground or a short circuit to the 12V battery supply along the Sensor Supply 2 lines.

4. 4

   Check ECU Connectors: Inspect the main 60-pin or 94-pin connectors at the Engine ECU for moisture, corrosion, or bent pins.

1. 1

   Turn off the machine, remove the key, and disconnect the negative battery cable.

   Turn off the machine, remove the key, and disconnect the negative battery cable.

2. 2

   Using a digital multimeter, verify the integrity of the wiring harness between the ECU and the sensors on the Supply 2 circuit.

   Repair any damaged wires or replace the engine harness section if a short is found.

3. 3

   If a sensor was identified as internally shorted during the diagnostic isolation test, replace the defective sensor.

   If a sensor was identified as internally shorted during the diagnostic isolation test, replace the defective sensor.

4. 4

   If the wiring harness tests perfectly and all sensors are unplugged but the ECU still fails to output a correct 5-volt signal on the Supply 2 pins, the ECU has suffered an internal Power Stage 2 failure.

   If the wiring harness tests perfectly and all sensors are unplugged but the ECU still fails to output a correct 5-volt signal on the Supply 2 pins, the ECU has suffered an internal Power Stage 2 failure.

5. 5

   Remove the defective Engine ECU by disconnecting the chassis and engine harnesses and unbolting it from the engine block mounting bracket.

   Remove the defective Engine ECU by disconnecting the chassis and engine harnesses and unbolting it from the engine block mounting bracket.

6. 6

   Install the replacement Engine ECU.

   Install the replacement Engine ECU.

7. 7

   A new or remanufactured ECU must be flashed/programmed with the correct engine dataset for your specific tractor PIN (serial number) using the Case IH Electronic Service Tool (EST).

   Self-learning parameters must also be restored.

8. 8

   Reconnect the battery, clear the inactive fault codes, and run the engine to verify the repair.

   Reconnect the battery, clear the inactive fault codes, and run the engine to verify the repair.