Case IH 17913 (F-3512-05) - ECU – Engine Control Module (ECM): ECM 5 volt sensor supply 4 under voltage failure.

The Engine Control Module (ECM) provides a 5-volt reference voltage (VREF) to power various engine and cab sensors on a shared circuit (Supply 4). This fault indicates that the ECM has detected the voltage on this specific circuit has dropped below the normal operating threshold. This is typically caused by a short to ground in the wiring harness, an open circuit, or an internally shorted sensor that is pulling the entire 5-volt reference circuit down.

• VESTRUM CVX
• Farmall 40
• Farmall 45
• Farmall 50

1. 1

   Verify Battery and ECM Power: Ensure the machine's batteries are fully charged and the ECM is receiving proper system voltage and ground.

2. 2

   Isolate the Circuit: Identify all sensors on the 'Sensor Supply 4' circuit (on many Case IH applications, this circuit powers the Accelerator Pedal Position Sensor or specific exhaust/aftertreatment sensors).

3. 3

   Sensor Disconnect Test: With the key ON (engine OFF), monitor the 5V supply voltage at the ECM or via a diagnostic scan tool. Unplug the sensors on this circuit one at a time. If the 5-volt reference returns to normal when a specific sensor is unplugged, that sensor is internally shorted and needs replacement.

4. 4

   Harness Inspection: If unplugging the sensors does not restore the 5V reference, use a multimeter to check the wiring harness between the ECM and the sensors for continuity to ground. Look for chafed, pinched, or melted wires rubbing against the engine block or chassis.

5. 5

   Pin Inspection: Inspect the ECM harness connectors for pushed-out pins, corrosion, or moisture intrusion.

1. 1

   Turn the ignition key to the OFF position and disconnect the negative battery cable to prevent electrical spikes.

   Turn the ignition key to the OFF position and disconnect the negative battery cable to prevent electrical spikes.

2. 2

   Based on your diagnostic findings, locate the point of failure (either the wiring harness or the specific shorted sensor).

   Based on your diagnostic findings, locate the point of failure (either the wiring harness or the specific shorted sensor).

3. 3

   If a wire is shorted to ground: Open the wire loom at the site of the chafe. Cut out the damaged section of the wire, solder in a new section of wire of the same gauge, and seal it with adhesive-lined heat shrink tubing. Re-loom and secure the harness away from vibration points.

   If a wire is shorted to ground: Open the wire loom at the site of the chafe. Cut out the damaged section of the wire, solder in a new section of wire of the same gauge, and seal it with adhesive-lined heat shrink tubing. Re-loom and secure the harness away from vibration points.

4. 4

   If a sensor is internally shorted: Remove the mounting hardware for the faulty sensor (e.g., the accelerator pedal assembly or throttle position sensor). Install the new OEM replacement sensor and torque the mounting bolts to factory specifications.

   If a sensor is internally shorted: Remove the mounting hardware for the faulty sensor (e.g., the accelerator pedal assembly or throttle position sensor). Install the new OEM replacement sensor and torque the mounting bolts to factory specifications.

5. 5

   Reconnect the sensor pigtail, ensuring the connector clicks and locks into place.

   Reconnect the sensor pigtail, ensuring the connector clicks and locks into place.

6. 6

   Reconnect the negative battery cable.

   Reconnect the negative battery cable.

7. 7

   Turn the key to the ON position and use a diagnostic scan tool to clear the inactive 17913 / 3512-05 fault code.

   Turn the key to the ON position and use a diagnostic scan tool to clear the inactive 17913 / 3512-05 fault code.

8. 8

   Start the engine and verify that the fault does not return and that the machine responds correctly to throttle inputs.

   Start the engine and verify that the fault does not return and that the machine responds correctly to throttle inputs.