System Voltage Malfunction
The engine control module has detected a problem with the system voltage.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The computer isn't getting the right voltage, indicating a battery or charging issue. It should see between 13.5 to 14.5 volts when the engine is running.
What the computer is actually seeing
The powertrain control module (PCM) monitors voltage levels from the battery and alternator. If it drops below a certain threshold, typically around 10.5 volts, it triggers this code.
What a healthy reading looks like
Battery voltage should be between 12.4 volts (off) and 14.0 volts (running).
Guided diagnostic — the DiagCoach way
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.
- 11. Check battery voltage with a multimeter. Should be 12.4V or higher (engine off).
- 22. Start the engine and check voltage again at the battery; it should be between 13.5V to 14.5V. If not, check the alternator output.
- 33. Inspect battery terminals for corrosion. Clean and tighten if necessary.
- 44. Check the wiring harness for any damage or loose connections between the battery and alternator, and between the alternator and ECU.
- 55. If voltages are still outside the expected range after checks, consider testing or replacing the alternator.
Common causes
- Dead battery
- Faulty alternator
- Loose or corroded battery connections
- Damaged wiring or connectors in the charging system
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's moderate severity. You can drive it but keep an eye on voltage; if the battery dies, you'll be stranded.
Will this code come back after clearing?
If the underlying issue isn't fixed, yes, it will likely return.
What might cause this code to appear intermittently?
Intermittent electrical issues like loose connections or corroded battery terminals can trigger this code.
Working a real vehicle right now?
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