Massey Ferguson E626.06 – Engine ECU: Grid heater relay current above normal or short to GROUND

The engine management system has detected that the electrical current flowing through the intake grid heater relay circuit is exceeding the normal operating range.

• 7616
• 5612
• 7622
• Interim Tier 4 (2012-2015)
• 7614
• 5611
• 7615
• 5610
• 5613
• 7620
• 5609
• 7618
• 5608
• 7619
• 7626
• 7624
• 5400 Series
• 5600 Series
• 6600 Series
• 6700S Series
• 7600 Series
• 7700 Series
• 7714
• 7715
• 8400 Series
• 8600 Series

1. 1

   Perform a relay swap test by exchanging the grid heater relay with an identical, known-good relay on the machine to see if the fault clears

2. 2

   Inspect the wiring harness running from the Engine ECU to the grid heater relay for chafed insulation, pinched wires, or exposed copper shorting to the engine block or chassis ground

3. 3

   Use a multimeter to test the relay control circuit for continuity to ground

1. 1

   Disconnect Power

   Disconnect the negative battery cable. The grid heater circuit carries high amperage, so isolating the battery is a critical safety step.

2. 2

   Locate the Relay

   Locate the grid heater relay. On many AGCO Sisu engines, it is mounted on the engine frame near the starter motor or integrated into the main engine harness block.

3. 3

   Repair Wiring

   If your diagnostic checks revealed a short to ground in the harness, repair the damaged section of wire using heat-shrink connectors and re-loom the harness to prevent future chafing.

4. 4

   Replace the Relay

   If the relay failed the swap test, unplug the 4-pin connector from the defective relay. Remove the mounting hardware, install the new 70-Amp relay, and plug the harness back in.

5. 5

   Clear Codes

   Reconnect the battery. Turn the ignition to the ON position and use a diagnostic service tool (such as the WinEEM3/EEM4 Service Tool) to clear the stored CAN messages and fault codes.

6. 6

   Verify Repair

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