System Voltage Low
Battery / charging system voltage seen by the ECU has dropped below the lower threshold (typically around 10.5 V). Modern ECUs are sensitive to under-voltage and may set this code briefly during cranking on a weak battery.
Affected components
- Battery
- Alternator
- Alternator belt
- Battery cables
Common causes
- High likelihood: Battery aged or weak
- Medium likelihood: Alternator undercharging
- Medium likelihood: Corroded battery terminals or ground strap
Diagnostic notes
- The malfunction indicator lamp may illuminate
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.