Case IH 17904 (F-3510-04) - ECU – Engine Control Module (ECM): ECM 5 volt sensor supply 2 high side output driver shorted to ground failure

The 5-volt reference circuit #2—which provides operating voltage to a specific group of engine/emissions sensors—has shorted to ground. When the Engine Control Module (ECM) detects that the voltage on this circuit has dropped below the acceptable threshold due to a short, it disables the output driver to protect the module and logs this code.

• VESTRUM CVX
• Stage V MR (Medium Range) tractors
• Farmall 115U Efficient Power
• Maxxum
• Puma

1. 1

   Perform a sensor isolation test by disconnecting sensors on the 5-volt supply #2 circuit one at a time (starting with UREA/DEF pressure and engine oil/boost sensors). Cycle the key to see if the fault changes to an open circuit or out of range code, indicating the last disconnected sensor is internally shorted.

2. 2

   Visually inspect the engine wiring harness between the ECM and the sensors on the Supply 2 circuit for chafing, melted insulation, or pinched wires against the engine block or frame.

3. 3

   Perform a multimeter continuity test by disconnecting the ECM and sensors, then measuring resistance between the 5V supply wire and a known good chassis ground. Continuity indicates a shorted harness.

4. 4

   Test the ECM output by turning the key ON with the harness disconnected and measuring voltage at the ECM's 5V Supply 2 pin. If it does not output 5 volts, the ECM driver may be damaged.

1. 1

   Power Down

   Turn the ignition OFF and disconnect the negative battery cable before disconnecting the ECM or repairing wiring.

2. 2

   Address the Short (Sensor)

   If a sensor is shorted: Replace the faulty sensor. Ensure the connector is clean and free of moisture or corrosion before installing the new sensor.

3. 3

   Address the Short (Harness)

   If the harness is shorted: Locate the chafed or melted section of the wire. Repair the wire using OEM-approved heat-shrink butt connectors, or replace that section of the engine wiring harness. Reroute the harness away from sharp edges or high-heat sources.

4. 4

   ECM Replacement

   If the harness and sensors test perfectly but the ECM fails to output 5 volts on the Supply 2 pin, the ECM must be replaced.

5. 5

   Reassembly and Verification

   Reconnect all sensors and the battery. Turn the key ON, clear the inactive fault codes using an electronic service tool (EST), and run the engine to verify the code does not return.