New Holland ENG 3268 – ENGINE controller (EDC - Electronic Diesel Control / Engine ECU): SCV(+) Output Open Load/Short to Ground; SCV(-) Output Open Load/Short to Ground; SCV coil open; SCV coil short.

The engine's computer has detected a critical electrical failure in the circuit for the Suction Control Valve (SCV) (also known as the Fuel Metering Unit). The system is seeing that the electrical circuit controlling the SCV is either completely broken (open load/coil open) or the wiring/coil has shorted out to ground or to another power source, causing the engine to run poorly, enter a derated 'limp' mode, or fail to start.

• L218
• L220
• SR175
• B90B
• B100B
• F5C engine
• F5H engine
• ISM-DI engine

1. 1

   Inspect the wiring harness running from the Engine ECU to the Suction Control Valve (SCV) for chafed wires, melted insulation, or breaks.

2. 2

   Disconnect the SCV electrical connector and check for pushed-out pins, corrosion, or moisture/diesel fuel contamination inside the plug.

3. 3

   Using a multimeter, measure the resistance across the pins of the SCV coil. An infinite reading indicates an open coil, while near zero indicates an internal short. Compare to OEM specs.

4. 4

   Check the continuity of the SCV(+) and SCV(-) wires from the SCV connector back to the Engine ECU pins. Test these wires for a short to ground (chassis) or a short to battery voltage.

5. 5

   If a diagnostic tool is available, monitor live data parameters such as 'Target SCV Current', 'Target Rail Pressure', and 'Actual Rail Pressure' to observe ECU commands.

1. 1

   Preparation

   Turn off the machine, remove the key, and disconnect the negative battery cable to prevent electrical shorts.

2. 2

   Locate and Clean

   Locate the high-pressure fuel pump on the engine block. The SCV is bolted directly to it. Thoroughly clean the area around the SCV with brake parts cleaner to ensure no dirt or debris enters the sensitive high-pressure fuel system during removal.

3. 3

   Disconnect

   Unplug the electrical connector from the SCV.

4. 4

   Removal

   Remove the retaining fasteners (typically Torx or Allen bolts) securing the SCV to the pump housing. Carefully twist and pull the SCV straight out of the pump.

5. 5

   Preparation of New Part

   Inspect the bore of the fuel pump for debris. Lubricate the O-rings on the new SCV with clean diesel fuel or clean engine oil to prevent tearing during installation.

6. 6

   Installation

   Push the new SCV squarely into the pump housing until it seats fully. Do not force it, as this can pinch the O-rings.

7. 7

   Secure

   Install the retaining fasteners and torque them to the OEM specification.

8. 8

   Reassembly

   Reconnect the SCV electrical connector and reconnect the battery.

9. 9

   Clear Codes

   Turn the key on, prime the fuel system if necessary, start the engine, and use a diagnostic tool to clear the ENG 3268 fault code. Verify that the code does not return and that rail pressure is stable.