Case IH 19728 – Engine Control Unit (ECU) / Engine Data Controller (EDC): Set-point of metering unit in overrun mode not plausible

This code indicates a discrepancy in the high-pressure fuel system. During overrun mode (engine deceleration or coasting), the engine control module commands the metering unit to reduce fuel flow to drop the fuel rail pressure. The fault triggers when the commanded set-point for the metering unit does not match the expected physical parameters, or the actual rail pressure fails to drop as expected, indicating the valve is likely sticking, mechanically failing, or receiving improper voltage.

• Tier 4b
• Magnum
• Steiger
• Puma
• Maxxum
• Optum
• Case IH N Series Loaders
• compact wheel loaders

1. 1

   Check for accompanying codes related to the Fuel Rail Pressure Sensor, Pressure Relief Valve (PRV), or CAN bus communication. A failing rail pressure sensor can trick the ECU into thinking the metering unit is malfunctioning.

2. 2

   Inspect the electrical connector and wiring at the fuel metering unit on the high-pressure pump for backed-out pins, corrosion, or chafed wires causing a short to ground or battery.

3. 3

   Monitor 'Desired Fuel Rail Pressure' versus 'Actual Fuel Rail Pressure' during engine overrun using the CNH Electronic Service Tool (EST). If actual pressure stays high while desired pressure drops, the metering unit is physically sticking.

4. 4

   Check fuel quality to ensure there is no heavy contamination or water in the fuel, which can cause the internal plunger of the metering unit to bind.

1. 1

   Disconnect Power

   Turn off the ignition and disconnect the battery ground cable.

2. 2

   Access the High-Pressure Pump

   Locate the high-pressure fuel pump on the engine block. The fuel metering unit is typically mounted to the rear or top of the pump with three Torx or Allen bolts.

3. 3

   Clean the Area

   Thoroughly clean the area around the metering unit with brake parts cleaner to prevent dirt from entering the high-pressure pump during removal.

4. 4

   Remove the Metering Unit

   Disconnect the electrical harness. Remove the mounting bolts and carefully pull the metering unit out of the pump housing.

5. 5

   Inspect for Debris

   Check the tip of the old metering unit and the bore of the pump for metal shavings. Note: If heavy metal shavings are found, the entire high-pressure pump has failed and the entire fuel system (lines, rails, injectors) must be flushed/replaced.

6. 6

   Install the New Unit

   Lubricate the O-rings on the new metering unit with clean diesel fuel. Carefully press it into the pump housing and torque the mounting bolts to OEM specifications.

7. 7

   Reassemble and Bleed

   Reconnect the electrical harness and battery. Turn the key to the ON position several times to allow the low-pressure lift pump to prime the system and bleed air.

8. 8

   Clear Codes

   Connect the CNH EST diagnostic tool, clear the 19728 fault code, and perform a test drive to verify the rail pressure drops correctly during deceleration.