P064FUnauthorized Software/Calibration Detected
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P064F means the module has found that its software or calibration is not the version released by the manufacturer, or fails an authenticity check (signature, checksum, security keys). CARB requires manufacturers to protect calibrations against changes without special tools and to report calibration IDs and checksums. GM's 2025 engine modules set it when the embedded message authentication table for secured bus messages is invalid, with the lamp in the first trip; chassis modules also check missing key storage or wrong key-slot configuration. Chrysler fixed P064F on the 2017 Ram 3500–5500 chassis cab 6.7 L Cummins by reprogramming – so it is not only about tuning. Typical triggers are tuning software, an interrupted or wrong reflash, a module from another vehicle, or a module replaced without learning its security keys. Programming released software usually clears it.
- What you may notice
- Check engine light (GM in the first trip)
- Possibly follow-up codes in other modules or communication problems
- Driving often normal
- Likely causes
- LikelyUnapproved or tuned software (chip tuning, programmer)
- PossibleFaulty or interrupted reflash, outdated software
- PossibleUsed or replaced module without learning the security keys, wrong configuration
- RareModule faulty internally (key storage)
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €80 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.