New Holland ENG 3651 – ENGINE: Battery Voltage: SRC low for battery voltage sensor

This fault indicates that the battery voltage supply to the Engine Control Unit (ECU) has dropped below the minimum required threshold. This fault can occasionally be triggered during a cold start if the battery voltage drops while the engine speed is less than 300 RPM and the coolant temperature is below 0 °C (32 °F).

• T4
• T5
• T5.95
• T5.105
• T5.115
• T6
• T7
• 200 Series
• L-Series
• L465
• LX465
• LX485
• SR175
• SR210
• SV250
• TR270
• TV370
• W50C
• W60C
• W70C
• W80C
• 21F
• 121F
• 221F
• 321F
• CR9090
• CX8080 Elevation
• CX8090 Elevation

1. 1

   Verify if the fault is currently active or if it was a stored code triggered by a cold start.

2. 2

   Measure the battery resting voltage with a multimeter and perform a load test to ensure the battery can hold a charge.

3. 3

   Start the engine and measure the voltage at the battery terminals to verify the alternator is charging properly (should typically read around 13.5V - 14.5V).

4. 4

   Inspect the wiring harness and connectors between the battery, alternator, and the ECU for loose grounds, corroded terminals, or damaged wires.

1. 1

   Clear and Retest

   If the machine was recently cold-started in freezing temperatures, clear the code and run the machine to see if it returns.

2. 2

   Clean Connections

   If the battery voltage is normal but the code persists, clean the battery terminals, chassis ground connections, and the ECU power connectors.

3. 3

   Replace the Battery

   If the battery fails a load test or cannot maintain proper resting voltage, replace it.

4. 4

   Replace the Alternator

   If the alternator is not outputting sufficient voltage to charge the battery and power the ECU, replace the alternator.

5. 5

   ECU Replacement

   If the battery, alternator, and wiring harness all test perfectly but the ECU still internally reads low voltage, the ECU itself may be faulty and require replacement/reprogramming.