Massey Ferguson E9172 – Engine Control Unit (ECU): Starter relay control

The control module has detected an electrical anomaly in the circuit responsible for triggering the starter relay.

• 8600 Series
• 8650
• 8660
• 8670
• 8680
• 8690
• 5400 Series
• 6400 Series
• 7400 Series
• 7600 Series
• 7700 Series

1. 1

   Check the battery voltage and ensure all battery terminals and heavy earth straps are clean and tight.

2. 2

   Turn the ignition key and listen for a click from the starter relay to determine if contacts are burnt or if the coil/signal is dead.

3. 3

   Test the wiring between the ignition switch, the ECU, and the starter relay socket for open circuits or shorts to ground/battery positive.

4. 4

   Inspect the starter motor solenoid to ensure it isn't seized or suffering from burnt contacts.

5. 5

   Check the engine cooling system if the tractor struggles to start when hot, as overheating can worsen electrical resistance.

1. 1

   Disconnect battery

   Disconnect the negative battery terminal to prevent accidental shorts.

2. 2

   Locate starter relay

   Locate the starter relay (typically housed in the main fuse/relay panel or near the ECU/starter, depending on the exact cab configuration).

3. 3

   Remove faulty relay

   Remove the faulty 4-pin starter relay.

4. 4

   Inspect and clean socket

   Inspect the relay socket for melted plastic, pushed-out pins, or green corrosion. Clean the terminals with electrical contact cleaner if necessary.

5. 5

   Install new relay

   Plug the new direct-replacement 4-pin relay into the socket (no wire splicing is required).

6. 6

   Verify repair

   Reconnect the battery, turn the ignition, and verify that the tractor cranks and the E9172 code is cleared.