Case IH 3168 (F-4009-05) - ECU – Engine Control Unit (ECU): Fuel filter heater actuator has an open load error

The Electronic Control Unit (ECU) has detected an open circuit condition in the signal circuit for the fuel filter heater relay.

• VESTRUM CVX
• Magnum Series (235-340 Series 4, MX210, MX230, MX255, MX285)
• Steiger Series
• Puma Series (140, 145, 165, 210)
• Farmall Series
• 240 Series Combines

1. 1

   Verify Power Supply: Check that the tractor battery has not been connected to an external power supply. If an external power supply is connected, disconnect it and test the system for normal operation.

2. 2

   Circuit Inspection: The ECU (A-095) monitors the fuel filter heater relay (K-024) signal circuit. Check this specific circuit for an open condition.

3. 3

   Relay Testing: Inspect the K-024 relay coil to see if it has failed or burnt out, which would cause the open load.

1. 1

   Power Down

   Turn off the machine and ensure no external power supplies or jump-starters are connected to the battery.

2. 2

   Locate the Relay

   Access the machine's power distribution box or relay panel and locate the fuel filter heater relay, identified in the schematics as K-024.

3. 3

   Inspect Wiring

   Visually inspect the wiring harness between the Engine ECU and the K-024 relay socket. Look for broken wires, backed-out pins, or corrosion that would cause an open circuit.

4. 4

   Test/Replace the Relay

   Remove the K-024 relay and test the coil for continuity. If the coil is open (infinite resistance), the relay is faulty and must be replaced.

5. 5

   Inspect the Heater Actuator

   If the relay and wiring to the ECU are intact, inspect the wiring from the relay to the fuel filter heater element itself, and test the heater element for an open circuit.

6. 6

   Clear Codes

   After repairing the wiring or replacing the faulty relay/heater, restore power and clear the ECU fault codes.