4 Isuzu diagnostic codes on file — with the full diagnosis, repair steps, and field insights open to read free, no signup required.
Disclaimer: General reference information for trained, qualified technicians only. Codes and procedures vary by model, serial number and software version. Always follow the manufacturer's service manual and your site's safety procedures. Use at your own risk. Not affiliated with or endorsed by any manufacturer.
| Code | System | Symptom | Full fix |
|---|---|---|---|
| P0400 | Emissions / EGR | Check Engine Light / Hesitation | View fix |
| P0401 | Emissions / EGR | Engine Pinging / Hesitation at Low RPM | View fix |
| P0402 | Emissions | Excessive black smoke; Poor fuel economy. | View fix |
| P1421 | Emissions / DPF | Frequent Regens / DPF Face Loading | View fix |
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