Massey Ferguson E9171 – Engine Control Unit (ECU): Preheating device control

Electrical malfunction within the engine's cold-start preheating system (which controls the intake air heater or glow plugs). Sub-codes indicate an open circuit (E 9171 5) or a short circuit to earth (E 9171 6).

• Massey Ferguson 8600 Series
• MF 8650
• MF 8660
• MF 8670
• MF 8680
• MF 8690

1. 1

   Check battery and terminals to ensure connections are secure, fully charged, and free from dirt, as cold weather increases starting system load.

2. 2

   Inspect the wiring harness between the Engine ECU, the preheater relay, and the heater element for chafing, breaks, or disconnected plugs.

3. 3

   Check the power supply to the preheater.

4. 4

   Verify the preheater relay and timer operation.

5. 5

   Test the preheater element (intake heater or glow plug) for proper electrical continuity.

1. 1

   Disconnect battery

   Disconnect the battery to prevent accidental shorts.

2. 2

   Locate components

   Locate the preheating device control relay and the intake heater element on the engine block.

3. 3

   Replace pre-heater unit

   If continuity testing reveals a failed heater element (open circuit), remove and replace the pre-heater unit.

4. 4

   Replace control relay

   If the relay fails to switch power to the element, replace the preheater control relay.

5. 5

   Repair wiring harness

   Repair any damaged sections of the wiring harness showing a short to earth.

6. 6

   Verify system operation

   Reconnect the battery and cycle the ignition to the 'Heat' (glow plug preheat) position to verify the system operates without triggering the code. Note: Contact your dealer if the code persists, as it may require OEM software to clear or recalibrate the ECU.