SCT X4 Performance Programmer

'20-'21 Ford F-250/F-350 6.7L Tuning Instructions

This document provides instructions for using the SCT X4 Performance Programmer to tune the Engine Control Unit (ECU) and Transmission Control Unit (TCU) of 2020-2021 Ford F-250/F-350 vehicles equipped with the 6.7L engine. It covers the setup process, tuning procedures, and returning the vehicle's systems to their stock configuration.

Image: A visual representation of the SCT X4 Performance Programmer device alongside an image of a 2020-2021 Ford F-250/F-350 truck.

Setup

Ensure the vehicle is turned off and parked safely.
Fully open the hood and ensure it is secured.
Locate the ECU in the firewall on the passenger's side of the vehicle.
Image: Engine bay of a Ford F-250/F-350, highlighting the ECU's location in the firewall on the passenger's side.
Release the locking tab on the gray connector arm before moving it. Disconnect all 3 of the ECU connectors.
Note: It is mandatory to disconnect ALL 3 ECU connectors when installing or uninstalling a tune.
Image: Close-up of ECU connectors. One image shows a green arrow pointing to a locking tab on a connector. Another image shows three ECU connectors labeled 1, 2, and 3.
Connect the ECU connector provided with the X4 to connection 1 on the ECU and to the SCT box.
Image: ECU connector being plugged into the ECU.
Connect the X4 device to the SCT box using the OBDII cable.
Image: SCT X4 device being connected to the SCT box via cable.
Connect the SCT box to the vehicle's battery using the provided battery clamps.
Important: Install the battery clamps with the Red clamp connected to the positive terminal and the black clamp connected to the negative terminal.
Image: SCT box being connected to a vehicle battery using red and black clamps.

Tuning Your ECU

Confirm that the setup steps on Page 1 and 2 have been completed.
On the X4 device, select "PROGRAM VEHICLE".
Image: Screenshot of the SCT X4 device's main menu, with "PROGRAM VEHICLE" highlighted.
Review and accept the "STREET USE NOTICE".
Image: Screenshot of the SCT X4 device displaying the "STREET USE NOTICE". This notice states that the device is not legal for sale or use in California on pollution-controlled motor vehicles and prompts the user to press "CONTINUE" to start programming.
Select the desired Custom Tune file to program.
If this is your first time flashing the vehicle, the device will display "SAVING STOCK DATA". This is a normal part of the process.
Image: Screenshot of the SCT X4 device displaying "PROGRAM VEHICLE" and "SAVING STOCK DATA" with a progress indicator showing 6%.
The X4 will now program the custom tune file into the vehicle. Upon completion, disconnect the battery clamps and reconnect all 3 ECU connections.
Image: Screenshot of the SCT X4 device displaying "PROGRAM VEHICLE" and "WRITING TUNE TO VEHICLE" with a progress indicator showing 8%.
Image: Screenshot of the SCT X4 device displaying "PROGRAM VEHICLE" and "DOWNLOAD COMPLETE" with a "DONE" button.

Tuning Your TCU

Your ECU is now tuned. Plug the X4 OBDII cable into your vehicle's OBDII port (typically located under the dashboard) to begin programming your TCU.
On the X4 device, select "PROGRAM VEHICLE".
Image: Screenshot of the SCT X4 device's main menu, with "PROGRAM VEHICLE" highlighted.
Review and accept the "STREET USE NOTICE".
Image: Screenshot of the SCT X4 device displaying the "STREET USE NOTICE". This notice states that the device is not legal for sale or use in California on pollution-controlled motor vehicles and prompts the user to press "CONTINUE" to start programming.
Follow the on-screen prompts provided by the device.
If this is your first flash, the device will display "SAVING STOCK DATA". This is a normal part of the process.
Image: Screenshot of the SCT X4 device displaying "PROGRAM VEHICLE" and "SAVING STOCK DATA" with a progress indicator showing 4%.
Image: Screenshot of the SCT X4 device displaying "PROGRAM VEHICLE" and "PREPARING PROCESSOR" with a progress indicator showing 37%.
After the stock data has been saved, the device will begin the tuning process.
Image: Screenshot of the SCT X4 device displaying "PROGRAM VEHICLE" and "TCU-Downloading Tune" with a progress indicator showing 60%.
When the process is complete, turn the vehicle's key off and select "DONE" on the device to return to the main menu. The tuning process is now complete, and you can disconnect the X4.
Image: Screenshot of the SCT X4 device displaying "PROGRAM VEHICLE" and "DOWNLOAD COMPLETE" with a "DONE" button.

Return Your ECU to Stock

Ensure that the setup steps on Page 1 and 2 have been completed.
On the X4 device, select "PROGRAM VEHICLE".
Image: Screenshot of the SCT X4 device's main menu, with "PROGRAM VEHICLE" highlighted.
Review and accept the "STREET USE NOTICE", then press "RETURN TO STOCK".
Image: Screenshot of the SCT X4 device displaying the "STREET USE NOTICE". This notice states that the device is not legal for sale or use in California on pollution-controlled motor vehicles and prompts the user to press "CONTINUE" to start programming.
Image: Screenshot of the SCT X4 device displaying "PROGRAM VEHICLE" and "RETURN TO STOCK" with a prompt to press "CONFIRM".
Confirm the action to return the vehicle to stock.
The X4 will now program the stock file into the vehicle.
Image: Screenshot of the SCT X4 device displaying "PROGRAM VEHICLE" with a progress indicator showing 4%.
When the process is complete, reconnect the ECU.
Image: Screenshot of the SCT X4 device displaying "PROGRAM VEHICLE" and "DOWNLOAD COMPLETE" with a "DONE" button.

Return Your TCU to Stock

Plug the X4 into the vehicle's OBDII port.
On the X4 device, select "PROGRAM VEHICLE".
Image: Screenshot of the SCT X4 device's main menu, with "PROGRAM VEHICLE" highlighted.
Review and accept the "STREET USE NOTICE", then press "RETURN TO STOCK".
Image: Screenshot of the SCT X4 device displaying the "STREET USE NOTICE". This notice states that the device is not legal for sale or use in California on pollution-controlled motor vehicles and prompts the user to press "CONTINUE" to start programming.
Image: Screenshot of the SCT X4 device displaying "PROGRAM VEHICLE" and "RETURN TO STOCK" with a prompt to press "CONFIRM".
Confirm the action to return the vehicle to stock.
The X4 will now program the stock file into the vehicle.
Image: Screenshot of the SCT X4 device displaying "PROGRAM VEHICLE" with a progress indicator showing 4%.
Your vehicle is now back to stock.
Image: Screenshot of the SCT X4 device displaying "PROGRAM VEHICLE" and "DOWNLOAD COMPLETE" with a "DONE" button.

LiveLink Gen-II / Advantage III Requirements

To use LiveLink with the 2020-2021 F-250/F350 6.7L, please update to the current release version, including any outstanding database updates.

LiveLink Gen-II: Version 2.9.4.0 or newer, including any outstanding database updates.
Advantage 3: Version 3.4 Build 22305.0 or newer.