P064F
Unauthorized Software/Calibration Detected.
- Generic
- Powertrain
- Generic code
- Medium severity
How this code is built
- P
- SystemPowertrain
- 0
- Defined bySAE, the same on every car
- 6
- AreaComputer and output circuits
- 4F
- FaultThe specific fault in that area
What it means
P064F means a control module has checked its own software or calibration and found it does not match what it expects, or it failed an authenticity or integrity check. The module usually does this by comparing stored identifiers or checksums with the approved data. How the check works and which module reports it depends on the vehicle.
Symptoms
- Engine warning light on
- Reduced power or limp mode on some vehicles
- Poor running, rough idle or hesitation
- Engine that is hard to start or will not start on some models
- Other codes stored at the same time, such as communication or internal control module faults
Possible causes
- Non-approved or modified software or calibration loaded into the module, for example an aftermarket remaplikely
- Interrupted or failed software update or reprogramming, leaving corrupted or incomplete datalikely
- Replacement or second-hand module fitted with the wrong software version or not programmed to the vehiclepossible
- Low battery voltage or unstable power supply during programming or operation corrupting the memorypossible
- Outdated calibration that the manufacturer has since superseded, where the module and its data no longer matchpossible
- Internal module fault such as failed memory or processorrare
- Wiring, earth or connector fault causing resets or communication errors in the modulerare
How to diagnose
- Read all stored and pending codes from every module and note any communication, low-voltage or internal module faults alongside P064F
- Review the freeze frame data and note when the code set, and whether it returned straight after clearing
- Ask about the vehicle's history: tuning, software updates, module replacement, recent battery disconnection or repair work
- Test the battery and charging system, and check voltage stability under load
- Inspect the module's connectors, power supplies and earths for corrosion, damage or looseness
- Read the software and calibration identification numbers from the module and compare them with the manufacturer's records for that exact vehicle and engine
- Check for manufacturer service bulletins or software updates relating to this code on the model
- Confirm the module part number and variant are correct for the vehicle if it has been replaced
How to fix
- Restore the manufacturer's approved software and calibration if a non-approved or modified file is installed
- Repeat the programming with a stable power supply if the last update failed or was interrupted
- Fit the correct module for the vehicle and programme and code it as the manufacturer specifies if the wrong or unprogrammed unit is installed
- Update to the latest approved calibration if the existing one is outdated and superseded
- Repair any wiring, earth or connector faults and correct battery or charging problems
- Replace the module and programme it to the vehicle if internal memory failure is confirmed
Can I keep driving?
Medium severity
The car can often be driven short distances, but behaviour may be unpredictable and it may drop into limp mode or fail to restart. Have it checked soon, and avoid long trips until the software or calibration issue is resolved.
Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.