Massey Ferguson E521002.04 – Engine ECU (AGCO SISU POWER EEM4): DEF Reverse Flow Solenoid Valve Low Voltage / DEF pump direction valve high side short circuit to GROUND

The engine management monitoring system has detected a short circuit to ground on the high side of the DEF pump direction valve.

• 7616
• 5612
• 7622
• Interim Tier 4 (2012-2015)
• 7614
• 5611
• 7615
• 5610
• 5613
• 7620
• 5609
• 7618
• 5608
• 7619
• 7626
• 7624
• MF 4707
• MF 4708
• MF 4709
• MF 4710
• MF 5608
• MF 5609
• MF 5610
• MF 5611
• MF 5612
• MF 5613
• MF 5710 SL
• MF 5711 SL
• MF 5712 SL
• MF 5713 SL
• MF 7614
• MF 7615
• MF 7616
• MF 7618
• MF 7619
• MF 7620
• MF 7622
• MF 7624
• MF 7626
• MF 7714
• MF 7715
• MF 7716
• MF 7716S
• MF 7718
• MF 7718S
• MF 7719
• MF 7720
• MF 7720S
• MF 7722
• MF 7722S
• MF 7724
• MF 7724S
• MF 7726
• MF 7726S

1. 1

   Perform a system reset by saving the error log, erasing it, and restarting the ECU (ignition off for at least 60 seconds, then back on)

2. 2

   Perform a drive cycle test to see if the fault returns during operation

3. 3

   Inspect the wiring harness between the Engine ECU and the DEF supply module using a multimeter to check for continuity and a short circuit to ground

4. 4

   If the wiring is intact and not shorting to the chassis, suspect a defective internal circuit in the DEF supply module

1. 1

   Disconnect battery

   Turn off the tractor and disconnect the battery to ensure safety while working on the electrical system.

2. 2

   Disconnect harness

   Locate the DEF Supply Module (DEF Pump) and disconnect its electrical harness.

3. 3

   Inspect connectors

   Inspect the harness connectors for corrosion, water ingress, or bent pins.

4. 4

   Inspect and repair wiring

   Trace the wiring harness back to the Engine ECU, looking for chafed insulation, pinched wires, or areas rubbing against the frame that could cause a short to ground. Repair any damaged wiring found.

5. 5

   Remove defective module

   If the wiring harness tests perfectly fine, remove the defective DEF Supply Module.

6. 6

   Install replacement module

   Install the replacement DEF Supply Module / Pump.

7. 7

   Reconnect harness and battery

   Reconnect the electrical harness and the battery.

8. 8

   Clear fault codes

   Use a diagnostic service tool to clear the fault codes from the EEM4 controller.

9. 9

   Test cycle

   Run the engine and perform a test cycle to ensure the DEF system primes, the warning lamp remains off, and the fault code does not return.