Massey Ferguson 677.03 – Engine ECU: Starter Relay Low Voltage

This code indicates that the voltage on the low-voltage side of the starter relay circuit has dropped below normal operating parameters. This usually points to excessive resistance in the starting circuit, a failing relay, burnt solenoid contacts, or a weak battery failing under load.

• 4710
• 7724S
• Interim Tier 4 (2012-2015)
• 7722S
• 7722
• 7615
• 5613
• 7720S
• 7716
• 7718
• 7726
• 7715
• 7616
• 7618
• 5608
• 4708
• 7619
• 7626
• 7726S
• 7624
• 4707
• 4709
• 7614
• 7718S
• 5610
• 7620
• 7719
• 7714
• 7716S
• T4 (2015-2021)
• 5612
• 7622
• 7720
• Tier 4 (2015-2021)
• 5611
• 7715S
• 5609
• 7724
• 5710SL
• 5711SL
• 5712SL
• 5713SL
• 7714S
• 7719S

1. 1

   Load test the battery to ensure it can handle cranking expectations (resting voltage must be adequate, and voltage at the starter solenoid should not drop below ~9.6 volts during cranking).

2. 2

   Inspect and clean battery terminals, main chassis grounds, and the heavy-gauge cables leading to the starter.

3. 3

   Locate the starter relay and test for proper switching and voltage drop across the pins.

4. 4

   Measure the voltage at the starter feed stud (solenoid output) while attempting to crank. If input voltage is good but output is poor, the solenoid's internal copper contacts are likely burnt or pitted.

1. 1

   Disconnect Power

   Always disconnect the negative battery cable before working on the starting circuit.

2. 2

   Replace the Starter Relay

   If the relay is found to be faulty or internally shorted/open, remove the 4-pin relay from the fuse/relay block and install a new OEM relay.

3. 3

   Inspect/Repair the Starter Solenoid

   If the relay is good but the solenoid clicks without cranking (and voltage drops across it), the heavy-duty copper contacts inside the solenoid are worn. Remove the starter motor from the tractor block, open the solenoid housing, and replace the internal copper contacts and plunger using a solenoid repair kit.

4. 4

   Replace Starter Motor (If Necessary)

   If the starter armature is seized, brushes are completely worn, or the housing is damaged, replace the entire starter motor assembly.

5. 5

   Clear Codes

   Reconnect the battery, turn the key to the ON position, and use the diagnostic menu or a scan tool to clear the 000677.03 code from the ECU. Test start the tractor to verify the repair.