Massey Ferguson 521010.14 – Engine ECU (EEM4): DEF tank heater coolant valve solenoid high side short circuit to HIGH SOURCE

The engine's monitoring system has detected that the high side of the circuit controlling the DEF tank heater coolant valve solenoid is shorted to a high voltage source (typically +12V).

• 7616
• 5612
• 7622
• Interim Tier 4 (2012-2015)
• 7614
• 5611
• 7615
• 5610
• 5613
• 7620
• 5609
• 7618
• 5608
• 7619
• 7626
• 7624
• 5600 Series
• 7600 Series
• 7617
• 8600 Series
• 8670
• 8690

1. 1

   Inspect the wiring harness connecting the EEM4 to the DEF tank heater coolant valve solenoid for chafed, melted, or pinched wires causing a short circuit to a +12V power source.

2. 2

   Disconnect the solenoid valve and test it for an internal short circuit.

3. 3

   Check the operation with a known-good DEF supply module to rule out a defective supply module.

1. 1

   Park the tractor on a level surface, turn off the engine, and disconnect the battery to prevent electrical damage.

   Park the tractor on a level surface, turn off the engine, and disconnect the battery to prevent electrical damage.

2. 2

   Locate the DEF tank heater coolant valve solenoid.

   Locate the DEF tank heater coolant valve solenoid (typically mounted near the DEF tank or integrated into the coolant lines routing to the DEF tank).

3. 3

   Disconnect the electrical connector to the solenoid valve.

   Disconnect the electrical connector to the solenoid valve.

4. 4

   Repair the wiring and replace the connector if necessary.

   If the diagnostic checks revealed damaged wiring in the harness (shorted to power), repair the wiring and replace the connector if necessary.

5. 5

   Replace the solenoid valve if internally shorted.

   If the wiring is intact but the solenoid is internally shorted, replace the solenoid valve. Note: You may need to clamp the coolant lines or partially drain the coolant to prevent spills when removing the valve.

6. 6

   Install the new DEF tank heater coolant valve solenoid.

   Install the new DEF tank heater coolant valve solenoid and reconnect the coolant lines and electrical connector.

7. 7

   Reconnect the battery.

   Reconnect the battery.

8. 8

   Clear the stored fault codes.

   Use a compatible diagnostic service tool (such as WinEEM4s or JPRO) to clear the stored fault codes.

9. 9

   Run the engine and verify the repair.

   Run the engine and verify that the warning lamp remains off and the code does not return.