How To Change The Save To AutoCal Number: EFILive Security And File Restriction Guide

To change the "Save to AutoCal" target serial number in EFILive V8 Scan and Tune, you must load the target calibration file, navigate to the File Properties Security restrictions, and update the 12-digit AutoCal serial number field. This authorization process requires a Master FlashScan device linked to the same tuner account to rewrite the security envelope without triggering an $0503 decryption error. Successful execution ensures that the encrypted tune file (.ctz or .coz) compiles correctly for the specific handheld device owned by your remote client.

Pre-Configuration and Software Requirements

Before attempting to modify the designated AutoCal restriction number in a tuning file, you must compile the correct software environment and verify hardware associations. EFILive enforces a strict master-slave cryptographic relationship between the Master FlashScan device (typically held by the professional calibrator) and the remote AutoCal hardware (held by the end-user). You cannot change the target restriction number of a file that was compiled by a different Master FlashScan unless you possess the original, unencrypted base tune (.ctz) file and the corresponding master security key.

Essential Tools and Prerequisites

• Software: EFILive V8 Scan and Tune software (Build 370 or newer recommended for full V3 hardware compatibility).
• Hardware: FlashScan V3 or FlashScan V2 Master device containing the active commercial license.
• Target Data: The exact 12-digit physical serial number of the destination AutoCal V2 or AutoCal V3 device.
• Base Files: The unencrypted master calibration file (.ctz or .coz format) matching the target controller (e.g., ECM/TCM).
• Estimated Duration: 10 to 15 minutes.
• Required Budget: Free (assuming existing ownership of licensed EFILive Master hardware and software).

Step-by-Step Guide to Modifying the Target AutoCal Serial Number

Follow this sequence to update the target restriction settings within the EFILive V8 environment. This procedure ensures that your exported tune files are keyed exclusively to the correct physical customer hardware.

Step 1: Initialize EFILive V8 Scan and Tune and Connect Master Hardware

Connect your FlashScan Master device to your PC using a high-quality USB A-to-B cable. Open the EFILive V8 Scan and Tune application from your desktop or start menu.

Warning: Do not attempt this process with only the client AutoCal connected. The software must detect the licensed Master FlashScan hardware to authorize changes within the security parameters of the restriction interface.

Verify that your FlashScan status indicator in the bottom right corner of the EFILive software displays a green checkmark, indicating active communication and a validated license structure.

Step 2: Load the Desired Calibration File

Navigate to the main menu screen of EFILive V8 and select the Tune option, then click on Open. Browse your local directories to locate the specific calibration file (.ctz or .coz) that requires the update to its AutoCal restriction designation. Double-click the file to load it into the calibration editor.

If the file is already locked to a different AutoCal serial number and you are not using the original Master FlashScan that created the lock, the software will prevent access. You must open the raw, unlocked master file from your database.

Step 3: Access the Security and Restriction Parameters

Once the calibration file is fully loaded into the editor interface:

1. Locate the horizontal tab menu running across the top of the calibration window.
2. Click on the F4: Properties tab to access the metadata and security layers of the active file.
3. Within the F4 sub-menu, locate the left-hand navigation pane and select the Restrictions option.

This panel displays the security constraints applied to the file upon saving, including permissions for reading, flashing, and device targeting.

Step 4: Update the AutoCal Restriction Serial Number

In the Restrictions configuration panel, locate the section labeled "AutoCal Remote Calibration". Here you will find the field dedicated to limiting the file's usability to a single device.

1. Ensure the checkbox labeled "Restrict to AutoCal with Serial Number" is checked.
2. Highlight the existing 12-digit serial number within the input text box.
3. Carefully type the new 12-digit serial number of the destination AutoCal device. Ensure there are no typographical errors; a single incorrect digit will cause a terminal validation failure when the end-user attempts to flash the vehicle.
4. If you wish to allow the file to be opened but not modified by the remote user, check the "Prevent Reading" box while leaving the target serial number restriction active.

Pro-Tip: The AutoCal serial number must be entered as a continuous string of 12 digits (e.g., 003568942105). Do not include any spaces, hyphens, or special characters.

Step 5: Save and Compile the Restructured File

After verifying the accuracy of the newly entered serial number, you must save the changes to generate a secure, encrypted file for distribution.

1. Click on the Save drop-down menu in the top-right corner or press Ctrl+S.
2. Select Save As to prevent overwriting your raw, master calibration file.
3. Rename the file to clearly reflect the target AutoCal user or serial number (e.g., E38_Stage1_AutoCal_003568942105.ctz).
4. Select the appropriate target directory and click Save. EFILive will automatically apply the cryptographic wrapper, locking the tune to the specified AutoCal hardware.

Hardware and File Restriction Compatibility Metrics

Different hardware generations and file types handle encryption, licensing, and save paths in distinct ways. The following table provides a reference for managing restrictions across the EFILive platform.

Resolving AutoCal Linking and File Locking Errors

When updating file restrictions, minor configuration mismatches can cause severe operational faults on the client's end. Below are the most common field failures and how to systematically resolve them.

Error Code $0503: "File is Not Licensed for This Device"

• Root Cause: This occurs when the 12-digit AutoCal serial number entered during the "Save to AutoCal" restriction step does not match the physical serial number of the handheld device trying to read or flash the file.
• Actionable Fix: Re-open the master tune file in EFILive V8. Navigate to F4: Properties -> Restrictions. Check the typed serial number against the physical serial number printed on the back label of the client's AutoCal, or have the client read the serial number directly from the hardware screen under Setup -> About. Re-enter the correct digits, resave the file, and send the new version to the user.

Error Code $0537: "Controller is Locked by Another Tuner"

• Root Cause: The calibration file contains security keys that do not match the target controller, or the engine control module (ECM) is locked with a custom key from a previous tuner.
• Actionable Fix: If the lock was applied by your own Master hardware, you must use your FlashScan to execute a full flash with the correct security key profile enabled. If the module was locked by an outside party, the controller must be physically bench-flashed to factory stock parameters using a high-voltage boot pin configuration or replaced with an unlocked module.

File Saving grayed out or "Read Only" Restrictions Active

• Root Cause: You are attempting to alter the restrictions on a tune file that has already been compiled and encrypted (.coz or .ctz) by another master tuner, or you do not have your Master FlashScan connected to authorize the change.
• Actionable Fix: Close the restricted file. Connect your registered Master FlashScan hardware via USB. Open the raw, unencrypted source file (.bin or unlocked .ctz). Re-apply the desired AutoCal serial number restriction within the F4: Properties tab and perform a fresh "Save As" operation.

Frequently Asked Questions

Can I change the target AutoCal number without having the physical AutoCal device in my possession?

Yes. As the master tuner, you only require the physical FlashScan Master hardware connected to your computer and the correct 12-digit serial number of the remote AutoCal device. The target AutoCal does not need to be physically present to receive the restricted file compilation.

Where is the target AutoCal serial number located if the sticker on the back is damaged or missing?

The end-user can locate the serial number electronically. They must plug the AutoCal into a USB port or vehicle OBD-II port, navigate the on-screen menu to "Setup", then select "About", and scroll down to view the "Serial Number" entry. Alternatively, they can connect the device to a PC, open the EFILive V8 Control Panel, and read the serial number from the "F1: Devices" tab.

Can an AutoCal device be linked to more than one Master FlashScan?

No. An AutoCal device is permanently linked to a single Master FlashScan custom key structure upon its initial deployment. To link an AutoCal to a different Master FlashScan, the current master tuner must generate an "Unlink Code," or the device must be returned to an authorized distributor for clean factory formatting, which erases all previous tuner associations.

What is the difference between a .ctz file and a .coz file when saving for an AutoCal?

A .ctz file contains both the operating system calibration data and the complete execution program for the controller, used for full-flashing or calibration-only flashing. A .coz file is a highly compressed, calibration-only format containing only the specific tables altered by the tuner. Both file formats support the exact same AutoCal serial number restriction profiles within EFILive V8.

Optimize Your Remote Tuning Workflow

Take control of your calibration distribution network by standardizing your security profiles inside EFILive V8. By mastering file restriction protocols, you protect your intellectual property while providing a seamless, error-free flashing experience for your remote clientele.