Battery Voltage Low - Battery Voltage Circuit Input Problem

The computer checks the battery voltage and expects it to be above 12.4 volts when the engine is off and above 13.5 volts when the engine is running. If it sees voltages below this, it sets the B1375 code.

The computer monitors battery voltage through an input circuit. If it detects voltage below 12.4 volts (engine off) or below 13.5 volts (engine running), it triggers the code.

Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.

1. 11. Inspect battery terminals for corrosion and ensure they are tight. Decision: Clean or tighten?
2. 22. Check battery voltage with a multimeter: should be above 12.4V (engine off) and above 13.5V (engine running). Decision: Is the voltage within range? (Yes = continue; No = replace the battery if dead or alternator if low)
3. 33. Inspect the wiring from the battery to the alternator for damage or corrosion. Decision: Are the wires intact? (Yes = continue; No = repair wiring)
4. 44. Check the alternator output voltage at the battery with the engine running. Should be 13.5V - 14.5V. Decision: Is alternator output adequate? (Yes = continue; No = replace alternator)
5. 55. If all else checks out, consider a defective battery monitor or control module.

• Weak or dead battery
• Corroded or loose battery terminals
• Faulty alternator
• Wiring issues in the battery or alternator circuit
• Faulty battery sensor

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