Massey Ferguson 000168.03 – ECU: Battery Voltage High

The Engine Control Unit (ECU) has detected that the battery supply voltage is excessively high, generally exceeding 16 volts and sometimes reaching up to 36 volts. This overcharging condition indicates a failure in the power supply or voltage regulation system, which poses a significant risk of damage to sensitive electronic components across the machine.

• 7600 Series
• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626
• 5600 Series
• 5700 Series
• 6600 Series
• 7700 Series
• 8700 Series

1. 1

   Visually inspect battery terminals, battery cables, and ground connections for corrosion, loose connections, or damaged wires.

2. 2

   Perform a load test on the battery to confirm it is in good condition (a fully charged 12V battery should read approximately 12.6 volts with the engine off).

3. 3

   Measure the charging system voltage directly at the battery terminals with the engine running at a fast idle (normal range is 13.5 to 14.5 volts; readings above 15-16 volts confirm overcharging).

4. 4

   Check for any other active fault codes, as a high voltage condition can trigger numerous secondary electrical and sensor faults.

1. 1

   Disconnect battery

   Disconnect the negative battery terminal to prevent electrical shorts.

2. 2

   Access alternator

   Remove side panels or other components as necessary to gain access to the alternator.

3. 3

   Release belt tension

   Loosen and release the tension on the serpentine or V-belt that drives the alternator pulley.

4. 4

   Disconnect wiring

   Carefully disconnect the main power cable and the wiring harness connector from the back of the alternator.

5. 5

   Remove alternator

   Unbolt the alternator from its mounting brackets and remove it from the engine, noting the position of any spacers or shims for correct reinstallation.

6. 6

   Install new alternator

   Mount the new alternator onto the engine, ensuring proper alignment, and reinstall the mounting bolts.

7. 7

   Reconnect and tension belt

   Reconnect the electrical wiring and reinstall the drive belt, ensuring it is tensioned correctly.

8. 8

   Perform final voltage check

   Reconnect the negative battery terminal, start the engine, and re-test the voltage at the battery terminals to confirm the new alternator is charging within the correct 13.5 to 14.5-volt range.