Powertrain, generic · Computer and auxiliary outputs

P064F Unauthorized Software/Calibration Detected

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

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.

Likely causes

Unapproved or tuned software (chip tuning, programmer)
Faulty or interrupted reflash, outdated software
Used or replaced module without learning the security keys, wrong configuration
Module faulty internally (key storage)

Symptoms

  • Check engine light (GM in the first trip)
  • Possibly follow-up codes in other modules or communication problems
  • Driving often normal

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–600
Time0.5–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

engine control modulecontrol module software

Related codes

P0601P0602P0605P0606P0630P0610

References: law.cornell.edu, gsi.ext.gm.com, gsi.ext.gm.com, static.nhtsa.gov.