Massey Ferguson E1076.04 – Engine Control Unit (ECU) / EEM4: MPROP control, Low side short circuit to GROUND

The system has detected that the low-side electrical circuit controlling the Magnetic Proportional Valve (MPROP) / Fuel Pressure Control Valve is shorted to ground.

• 7616
• 5612
• 7622
• Interim Tier 4 (2012-2015)
• 7614
• 5611
• 7615
• 5610
• 5613
• 7620
• 5609
• 7618
• 5608
• 7619
• 7626
• 7624
• 7600 series
• 8600 series

1. 1

   Carry out a preliminary inspection of the ECU unit connector, the high-pressure pump MPROP connector, and any intermediate harness connectors for dirty, worn, or badly positioned terminals.

2. 2

   Test the wiring harness between the ECU and the MPROP valve for a short circuit to ground on the low side.

3. 3

   Plug in a known-good MPROP solenoid valve to see if the fault clears, which would indicate an internal short in the original valve.

1. 1

   Disconnect battery

   Turn off the machine and disconnect the battery to prevent electrical spikes.

2. 2

   Locate MPROP valve

   Locate the MPROP / Fuel Control Valve on the back or top of the Bosch high-pressure fuel pump.

3. 3

   Inspect harness and pins

   Disconnect the electrical harness from the MPROP valve and inspect the pins for corrosion or damage.

4. 4

   Test and repair wiring

   Using a multimeter, check the low-side wire of the harness for continuity to ground. If a short is found, trace the harness back to the ECU and repair the chafed or melted wire.

5. 5

   Remove mounting screws

   If the harness tests good, the internal coil of the MPROP valve is shorted. Remove the mounting screws securing the MPROP valve to the high-pressure pump.

6. 6

   Remove defective valve

   Remove the defective valve. Ensure the mounting surface is clean and that no old O-rings are left inside the pump housing.

7. 7

   Insert new MPROP valve

   Lubricate the O-rings on the new MPROP valve with clean diesel fuel and carefully insert it into the pump.

8. 8

   Install mounting screws

   Install and tighten the mounting screws to the manufacturer's specified torque.

9. 9

   Reconnect and clear codes

   Reconnect the electrical harness, reconnect the battery, and clear the fault codes using a diagnostic service tool.

10. 10

    Verify repair

    Start the engine and verify that rail pressure is stable and the code does not return.