P064F: Unauthorized Software or Calibration Detected

What it means

The ECU's secure boot or signature check has detected calibration data that is not signed by the manufacturer - typically appears after chip-tuning or unauthorised flash programming. The ECU may run on safe defaults or refuse to start.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test

How it works

The engine control module checks whether its installed calibration carries an accepted digital signature during startup or operation. This code sets when the security check rejects the calibration, which can follow unauthorized tuning, interrupted programming, corrupted data, or a memory fault; the module may then use fallback settings or prevent starting.

Common causes

Most likely first.

1. Non-factory or unauthorized calibration installed
2. ECU reprogramming interrupted or incomplete
3. Corrupted calibration data
4. ECU memory or hardware fault

Symptoms

• Check engine light on
• Possible limp mode or no-start
• Multiple follow-up faults across modules
• Reset/relearn may be needed after repair

How to diagnose it

1. Save freeze-frame data and scan all modules for programming, immobilizer, and communication faults before attempting to clear the code.
2. Ask whether the engine control module was recently tuned, replaced, or reprogrammed, and check whether the current calibration is recognized by the vehicle's approved service information.
3. Inspect the module's power, ground, and connectors for interruptions or poor contact that could have disrupted a programming session.
4. Check for related low-voltage or network faults and correct them before any calibration work.
5. Use the manufacturer's approved programming process to verify calibration integrity and restore a valid signed calibration if the installed data is rejected.
6. If approved programming fails or the integrity fault returns with stable power and network connections, assess the module's memory and hardware.

Common fixes

• Restore the approved, correctly signed calibration using the manufacturer's programming process.
• Repair module power, ground, or network connections that interrupted programming.
• Repeat a failed or incomplete reprogramming procedure after correcting its underlying power or communication fault.
• Repair or replace the engine control module if its memory or hardware cannot retain a valid calibration.

Can I keep driving?

If the engine starts and runs, limit driving because fallback calibration can affect power and emissions; avoid trips where a sudden loss of power would be hazardous. If it will not start or enters limp mode, arrange repair before relying on the vehicle.