OBD-II FAULT CODE
P0621
Generator Lamp "L" Control Circuit Malfunction
Meaning, symptoms, likely causes, diagnostic checks and repair guidance for P0621.
- Check Engine light
- Poor drivability or reduced fuel economy depending on fault
- Blown bulb/LED module
- Poor ground
- Fuse/relay fault
- Switch/module/wiring issue
- Scan all modules and record freeze-frame data before clearing codes
- Check battery voltage and related fuses
- Check bulb/module, fuse, ground and connector corrosion
- Replace failed bulb/module, repair ground/wiring, replace switch/relay if confirmed
Related Codes
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Disclaimer: Information is provided for general guidance only and may not apply to all vehicles. Always consult a qualified technician.