Case IH 17666 (F-519757-31) - ECU – Engine Control Module (ECM / ECU): Fuel metering unit power stage failure

The engine's control system has detected an electrical short circuit or power stage malfunction in the circuit that controls the Fuel Metering Unit (also known as the M-PROP, Fuel Pressure Control Valve, or Quantity Control Valve), which regulates the amount of fuel entering the high-pressure fuel pump.

• VESTRUM CVX
• FPT Cursor 11 engines (Tier 3, Tier 4B, and Stage V MR)
• Case IH AUSTOFT 9900 sugarcane harvesters
• Case IH Farmall tractors (with FPT engines)
• Case IH Steiger tractors (with FPT engines)
• Case IH Puma tractors (with FPT engines)

1. 1

   Use the Electronic Service Tool (EST) to check if the fault code is currently active.

2. 2

   Inspect the wiring harness and connectors between the Engine ECU and the Fuel Metering Unit for loose contacts, broken insulation, or physical damage that could cause a short circuit between the high and low sides.

3. 3

   Check the electrical resistance of the fuel metering unit's solenoid coil to determine if the short circuit is internal to the unit itself.

1. 1

   Disconnect power

   Disconnect the battery ground cable before performing electrical repairs or replacing sensors/valves on the engine to prevent damage to the ECU.

2. 2

   Repair wiring harness

   If a short was found in the wiring harness during diagnostics, repair the broken insulation or replace the damaged connector/harness section.

3. 3

   Clean fuel pump area

   If the wiring is intact and the short is internal to the unit, prepare for replacement by thoroughly cleaning the area around the high-pressure fuel pump to prevent dirt from entering the fuel system.

4. 4

   Replace fuel metering unit

   Unbolt the defective fuel metering unit from the high-pressure fuel pump. Lubricate the O-rings on the new unit with clean diesel fuel prior to installation, then install the new unit.

5. 5

   Clear codes and verify

   Reconnect the battery, use the Electronic Service Tool (EST) to clear the inactive fault codes, and run the engine to verify that the fuel pressure is stable and the code does not return.