Massey Ferguson E521002.05 – Engine Control Unit (ECU): The DEF Reverse Flow Solenoid Valve Low Amps

A "Low Amps" fault indicates that the control module is detecting insufficient electrical current flowing through the DEF (Diesel Exhaust Fluid) reverse flow solenoid valve circuit. This typically points to an open circuit, high electrical resistance, a disconnected or corroded wiring harness, or a completely failed solenoid coil.

• 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
• 7600 Series Interim Tier 4 (2012-2015)

1. 1

   Visually inspect the wiring harness leading to the DEF reverse flow solenoid valve for chafed wires, broken lines, or rodent damage.

2. 2

   Disconnect the solenoid valve connector and check for water intrusion, bent pins, or corrosion.

3. 3

   Perform a resistance test (Ohms) across the pins of the solenoid valve. An infinite reading (OL) confirms the internal coil is broken (open circuit).

4. 4

   Test the wiring harness for continuity between the ECU and the solenoid connector to rule out a broken wire if the valve's resistance is normal.

1. 1

   Power Down

   Turn off the tractor and disconnect the negative battery terminal to prevent electrical shorts.

2. 2

   Locate the Component

   Locate the DEF supply module/pump assembly where the reverse flow solenoid is housed.

3. 3

   Clean the Area

   Thoroughly clean the area around the DEF pump to prevent dirt or crystallized DEF from entering the hydraulic lines.

4. 4

   Disconnect

   Unplug the electrical connector from the DEF reverse flow solenoid valve.

5. 5

   Remove the Valve

   Remove the retaining fasteners or clips holding the solenoid valve in place and carefully extract the valve.

6. 6

   Install the New Valve

   Lubricate the O-rings on the new solenoid valve with a small amount of clean DEF or approved assembly lube. Seat the valve into the housing and secure the fasteners.

7. 7

   Reconnect

   Plug the electrical connector back in, ensuring it clicks and locks securely.

8. 8

   Test

   Reconnect the battery. Turn the key on, clear the inactive fault codes using a diagnostic tool, and run the engine. Perform a manual DEF system purge/dosing test if your diagnostic tool supports it to verify the reverse flow function operates without throwing the low amps code.