Case IH 3167 (F-4009-04) - ECU – Engine Electronic Control Unit (ECU A-095): Fuel filter heater actuator (or relay) is shorted to ground

The FMI 04 designation indicates 'Voltage Below Normal / Shorted to low source'. The control module monitors the fuel filter heater relay (K-024) signal circuit. If a short to ground condition is detected in this circuit, the fault is triggered.

• VESTRUM CVX
• 240 Series (7240, 8240, 9240)
• Axial-Flow 5130
• Axial-Flow 7230
• Axial-Flow 8230
• Axial-Flow 9230
• Magnum Series (MX210-MX285, 235-340)
• Puma Series
• Farmall 40-45-50 Tractors

1. 1

   Verify that the machine's battery power supply has not been connected to an external power supply (like a jump box or charger). Disconnect if present and test for normal operation.

2. 2

   Check for accompanying codes (3166, 3168, or 3169). If present, the issue is almost certainly in the harness or relay.

3. 3

   Visually inspect the wiring harnesses and connectors between ECU A-095 and relay K-024 for damaged, bent, or dislocated pins, corroded terminals, or broken wires.

4. 4

   Perform a harness flex test while the machine is keyed on to reveal intermittent breaks or shorts to ground in the wiring.

1. 1

   Locate Relay K-024

   Access the machine's relay/fuse panel and locate the Fuel Filter Heater Relay, designated as K-024.

2. 2

   Test the Relay

   Remove relay K-024 and test the coil. If the relay coil is internally shorted to ground, replace the relay.

3. 3

   Test the Signal Circuit

   With the relay removed, use a multimeter to check the signal circuit wiring between the relay block and ECU A-095 for continuity to ground (involves wire 6570 GN and wire 6408 GN).

4. 4

   Repair Wiring

   If the signal circuit wire is shorted to the chassis/ground, trace the harness and repair the damaged section of the wire.

5. 5

   Software Verification

   If the relay and wiring test perfectly fine and the fault remains active, verify that the appropriate ECU A-095 software is present and reflash the ECU if necessary.