Case IH 518653-03 - ICM – ICM: Voltage fuel level sensor is shorted to VCC (power), has an open circuit, or is not configured

The control module is receiving a voltage signal from the fuel tank sending unit that is higher than the permissible range (short to power) or is receiving no signal at all (open circuit/broken wire). It can also trigger if the software loses the configuration data telling it that a fuel level sensor is present.

• MAGNUM AFS Connect
• Magnum series
• Magnum 400 AFS Connect
• Steiger series
• Puma series
• Maxxum models
• Axial-Flow series
• 2166
• 2388
• 7120

1. 1

   Visual Inspection: Check the electrical connector at the fuel level sensor (located on top of the fuel tank) for loose pins, corrosion, or physical damage.

2. 2

   Wiring Harness Test: Disconnect the sensor and use a multimeter to check the signal wire back to the ICM. Look for continuity (to rule out an open circuit) and check for voltage on the signal line with the sensor unplugged (to rule out a short to VCC/12V power).

3. 3

   Sensor Resistance Test: Measure the resistance across the fuel level sensor terminals. Depending on the exact model, standard sensors often read between 0-190 ohms. If the multimeter reads "OL" (Open Loop), the sensor is internally broken and must be replaced.

4. 4

   Configuration Check: If the machine was recently serviced or the ICM was flashed/replaced, use the Case IH Electronic Service Tool (EST) to verify that the fuel level sensor is actually configured as "Present" in the ICM software.

1. 1

   Prep the Machine

   Park the machine on a level surface, turn off the engine, remove the key, and disconnect the negative battery cable to prevent electrical shorts.

2. 2

   Locate the Sensor

   Access the top of the fuel tank. You may need to remove protective shielding or access panels depending on the tractor/combine model.

3. 3

   Clean the Area

   Thoroughly clean the area around the fuel level sensor to prevent dirt and debris from falling into the fuel tank during removal.

4. 4

   Disconnect

   Unplug the electrical harness connector from the sensor.

5. 5

   Remove the Sensor

   Using the appropriate wrench or socket, remove the mounting bolts or unscrew the retaining ring holding the sensor in place. Carefully pull the sensor assembly straight up and out of the tank.

6. 6

   Install the New Sensor

   Insert the replacement fuel level sensor into the tank, ensuring the new rubber gasket/O-ring is properly seated to prevent fuel leaks. Tighten the mounting hardware to OEM specifications.

7. 7

   Reconnect

   Plug the electrical harness back into the new sensor.

8. 8

   Test

   Reconnect the battery, turn the ignition to the ON position, and verify that the fuel gauge on the ICM registers the correct fuel level and that the 518653-03 fault code changes to "Inactive" or clears.