Massey Ferguson 168.01 – Engine ECU: Battery Voltage Low (ECU)

The measured voltage supplied to the Engine Control Unit has dropped below the normal operating range. This condition can cause power stages to be disabled and may result in engine power degradation or shutdown.

• 5710SL
• 5711SL
• 5712SL
• 5713SL
• T4
• 4707
• 4708
• 4709
• 4710
• 5608
• 5609
• 5610
• 5611
• 5612
• 5613
• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626
• 7714
• 7726S
• 9695
• 9795

1. 1

   Measure the static battery voltage at the battery posts and perform a load test to ensure the battery can hold a charge

2. 2

   With the engine running, check the voltage at the battery to verify the alternator is charging (should typically read around 13.5V - 14.4V)

3. 3

   Inspect the battery terminals, cables, and chassis ground connections for heavy corrosion, looseness, or fraying

4. 4

   Measure the voltage directly at the Engine ECU harness connector to check for a voltage drop (indicates high resistance, failing relay, or blown fuse)

1. 1

   Clean and Tighten Connections

   If corrosion or loose connections are found during diagnostics, disconnect the battery (negative first), clean the posts and terminals with a wire brush, reconnect, and tighten securely. Clear the code and retest.

2. 2

   Replace the Battery

   If the battery fails a load test or has a dead cell causing the voltage to drop below 7.8V, remove the battery hold-down clamp, swap in a new OEM-spec battery, and secure the connections.

3. 3

   Replace the Alternator

   If the battery is good but the alternator is failing to charge the system, disconnect the battery, remove the serpentine/drive belt, disconnect the alternator electrical connections, unbolt the alternator, and install a replacement.

4. 4

   Repair Wiring/Relays

   If the issue is isolated to the ECU power circuit, trace the wiring harness from the battery to the ECU. Repair any chafed wires and replace corroded fuses or the main ECU power relay.