Massey Ferguson E 626 (4) – Engine Control Unit (ECU) / EEM: Inlet air heater control, voltage below normal

The Engine Control Module (ECM) has detected that the voltage in the inlet air heater's control circuit is below the normal operating level. This condition indicates a potential open circuit, high resistance in the wiring, or a failure in the power supply to the heater's control solenoid or relay, which will negatively affect the proper operation of the inlet air heater during cold starts.

• 5400 Series
• 5600 Series
• 5608
• 5609
• 5610
• 6400 Series
• 6600 Series
• 6700 Series
• 7600 Series
• 7614 to 7622 Dyna-4/Dyna-6
• 7700 Series
• 7714
• 7715
• 7716
• 7718
• 7719
• 8400 Series
• 8600 Series

1. 1

   Inspect the wiring harness between the EEM (Engine Control Unit) and the grid heater relay for any visible damage, chafing, or signs of a short circuit to ground.

2. 2

   Test the grid heater relay (70 Amp, 4-pin) for proper continuity and ensure it is not stuck open or internally shorted.

3. 3

   Inspect the main engine fuses and the specific fuse dedicated to the inlet air heater circuit to ensure it hasn't blown due to a short.

4. 4

   Ensure the power cable connections at the inlet air heater solenoid and the relay are clean, tight, and free of corrosion.

1. 1

   Disconnect Power

   Always disconnect the negative (-) battery terminal before maintaining or repairing the electrical circuit to prevent shorts or ECU damage.

2. 2

   Access the Relay

   Locate the grid heater relay block (refer to your specific model's fuse/relay box diagram).

3. 3

   Repair Wiring (If Applicable)

   If the diagnostic checks revealed a short to ground or a broken wire in the harness between the ECU and the relay, splice and repair the wire using weather-sealed connectors.

4. 4

   Replace the Relay

   If the wiring is intact but the relay failed testing, remove the faulty 4-pin grid heater relay and install the replacement.

5. 5

   Reassemble and Test

   Reconnect the negative battery terminal. Turn the ignition on to allow the EEM to run its self-check.

6. 6

   Clear Codes

   Use an AGCO diagnostic service tool (or perform a system reset by turning the ignition off for at least 60 seconds, then back on) to clear the stored CAN message and verify the warning light extinguishes.