Massey Ferguson E9174 – Engine ECU: MPROP pump control

The MPROP valve (Magnetic Proportional Valve) regulates the volume of fuel entering the high-pressure system to maintain the desired fuel rail pressure. The code indicates an electrical condition such as a short circuit to battery, open circuit, short circuit to ground, or excessive temperature.

• Massey Ferguson 8600 series
• MF 8650
• Massey Ferguson 7600 series
• MF 7600

1. 1

   Inspect the two-wire pigtail connector and wiring harness leading to the MPROP valve on the back of the injection pump for chafing, breaks, or melted insulation.

2. 2

   Use a multimeter to test the continuity of the wiring between the Engine ECU and the MPROP valve to rule out an open or short circuit.

3. 3

   Connect a diagnostic scan tool to monitor desired vs. actual fuel rail pressure. A failing MPROP valve will cause actual pressure to fluctuate wildly from desired pressure.

1. 1

   Clean area

   Clean the area around the high-pressure fuel pump (Bosch CP3.3) thoroughly to prevent any dirt or debris from entering the fuel system.

2. 2

   Disconnect connector

   Disconnect the electrical connector from the MPROP valve.

3. 3

   Remove screws

   Remove the three (3) T-25 Torx head screws securing the MPROP valve to the back of the CP3 pump.

4. 4

   Remove valve

   Carefully pull the old MPROP valve out of the pump housing.

5. 5

   Lubricate O-rings

   Lubricate the O-rings on the new MPROP valve with clean diesel fuel.

6. 6

   Install new valve

   Insert the new valve into the pump housing and tighten the three T-25 Torx screws securely.

7. 7

   Reconnect connector

   Reconnect the electrical connector.

8. 8

   Bleed and verify

   Bleed the fuel system if necessary, start the engine, and use a scan tool to clear the E9174 fault code. Verify that the idle is stable and rail pressure matches the commanded pressure.