Massey Ferguson E4332.11 – Engine ECU: DEF Pump/ Pressure Issue

The DEF (Diesel Exhaust Fluid) metering pump is failing to generate or maintain the correct pressure required for the SCR (Selective Catalytic Reduction) system, or there is an internal mechanical/electrical fault within the pump itself.

• 7616
• 5612
• 7622
• Interim Tier 4 (2012-2015)
• 7614
• 5611
• 7615
• 5610
• 5613
• 7620
• 5609
• 7618
• 5608
• 7619
• 7626
• 7624
• MF 7614
• MF 7615
• MF 7616
• MF 7618
• MF 7619
• MF 7620
• MF 7622
• MF 7624
• MF 7626
• MF 5608
• MF 5609
• MF 5610
• MF 5611
• MF 5612
• MF 5613
• MF 4707
• MF 4708
• MF 4709
• MF 4710
• MF 7714 through 7726S
• MF 5710 SL
• MF 5711 SL
• MF 5712 SL
• MF 5713 SL

1. 1

   Fluid Quality & Contamination Check: Use a refractometer to test the DEF concentration (it should be exactly 32.5%). Check the tank for contamination (dirt, diesel, or water), which can destroy the pump.

2. 2

   Visual Inspection for Crystallization: Inspect the DEF pump, dosing injector, and tailpipe for white crystalline crusts. This indicates a leak or a purge failure that can cause blockages.

3. 3

   Filter Inspection: A clogged DEF filter can starve the pump and cause pressure faults. Check the DEF filter module.

4. 4

   Line Inspection: Inspect the DEF suction and pressure lines for kinks, leaks, or blockages.

5. 5

   Electrical & Sensor Check: Inspect the wiring harness and connectors to the DEF pump for corrosion or damaged pins. Ensure the DEF pressure sensor is reading correctly, as a faulty sensor can mimic a dosing pump issue.

1. 1

   Preparation

   Turn off the tractor and remove the key. Important: Wait at least 5-10 minutes before disconnecting the battery to allow the SCR system to complete its automatic purge cycle (draining DEF back into the tank to prevent freezing/crystallization).

2. 2

   Disconnect Battery

   Once the purge is complete, disconnect the negative battery terminal.

3. 3

   Access the Pump

   Locate the DEF metering pump module (typically mounted near the DEF tank).

4. 4

   Disconnect Lines & Wiring

   Carefully disconnect the electrical harness from the DEF pump. Disconnect the DEF supply, return, and dosing lines. Note: Have warm water ready to clean up any spilled DEF immediately, as it is highly corrosive to metal and crystallizes quickly.

5. 5

   Removal

   Unbolt the DEF pump assembly from its mounting bracket and remove it from the tractor.

6. 6

   Installation

   Mount the new DEF metering pump to the bracket and secure the bolts.

7. 7

   Reconnection

   Reconnect the DEF lines, ensuring the quick-connect fittings click securely into place. Reconnect the electrical harness.

8. 8

   Filter Replacement

   It is highly recommended to install a new DEF filter element when replacing the pump to prevent immediate contamination of the new unit.

9. 9

   Testing

   Reconnect the battery. Turn the ignition on to allow the system to prime. Check all connections for leaks. Use a diagnostic scan tool to clear the E4332.11 fault code and run a forced DEF system pressure test to verify the repair.