Case IH 4 – Electronic Instrument Cluster (EIC) or Advanced Display Instrument Cluster (ADIC): Fuel tank level sender open circuit or short to + voltage

The control module is receiving an abnormally high voltage signal from the fuel level sender circuit. This condition is almost always caused by a broken or disconnected signal wire (open circuit), the signal wire chafing and touching a power source (short to + voltage), or an internal failure of the fuel sender unit itself.

• MXM
• MXM Series
• MXM 120
• MXM 130
• MXM 140
• MXM 155
• MXM 175
• MXM 190
• MX Series
• Magnum
• Steiger

1. 1

   Visually inspect the fuel level sender on the fuel tank to ensure connectors are clean, tight, and free of corrosion.

2. 2

   Perform a ground circuit test: disconnect wires from the sender and connector C079 from the instrument panel. Check the ground wire (e.g., C022-RM2095-G/W/B) to chassis ground (resistance should be <10 ohms). If higher, locate and repair the open circuit in the ground wire.

3. 3

   Perform a signal wire test: measure resistance between instrument panel connector pins (e.g., J1-10 and J1-7) (should be <5000 ohms). If it reads open line (OL), check the signal wire for breaks or test for continuity from the sender harness to the cluster harness.

4. 4

   Perform a voltage check: with the key ON, check the signal wire for voltage. If it shows a full 12V when disconnected from the cluster, the wire is shorted to a power source in the harness.

5. 5

   Isolate the sender: if the wiring harness passes all continuity and ground checks, the fault is internal to the fuel tank level sender and it must be replaced.

1. 1

   Prepare machine

   Park the machine on a level surface, turn off the engine, and disconnect the negative battery cable.

2. 2

   Locate sender

   Locate the fuel tank level sender (usually accessed from the top or upper side of the fuel tank). Note: On some models like the MX series, ensure the cab A/C ducting or rails haven't dropped and crushed the sender, which is a known cause of wiring damage.

3. 3

   Disconnect harness

   Disconnect the electrical harness connector from the sender unit.

4. 4

   Clean area

   Thoroughly clean the area around the sender to prevent dirt and debris from falling into the fuel tank.

5. 5

   Remove retaining hardware

   Remove the retaining screws or twist off the locking ring holding the sender in place.

6. 6

   Remove old sender

   Carefully pull the old sender unit and its attached float arm out of the tank.

7. 7

   Insert new sender

   Insert the new sender unit, ensuring the new rubber gasket/seal is properly seated to prevent fuel leaks.

8. 8

   Secure new sender

   Reinstall and tighten the retaining screws or locking ring.

9. 9

   Reconnect harness

   Reconnect the electrical harness.

10. 10

    Verify repair

    Reconnect the battery, turn the ignition key to the ON position, and verify that the fuel gauge reads accurately and Fault Code 4 is cleared.