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Spare ECU Install Instructions

SXTH Element Spare ECU Installation Guide

Required Tools and Equipment

  • EK1 Device
  • Bench Cable (required for 2024+ Elantra N models)
  • 10mm Socket and Wrench

Step 1: Obtain the VIN Writing File

  1. Submit a Ticket: Visit sxthnktuning.com and submit a support ticket. Include your full VIN and indicate that you need a VIN writing file.
  2. Receive the VIN File: We will provide you with the VIN writing file, which should be placed in the INIT folder of your EK1 device's SD card.

Step 2: Prepare the Vehicle

  1. Remove the Original ECU: Open the engine bay and use the 10mm socket and wrench to remove the original ECU.
  2. Install the New ECU: Replace the original ECU with the new spare ECU.
  3. Accessory Mode: Put the vehicle in accessory mode, but do not attempt to start the car.
  4. Connect EK1 to OBDII: Or, if your vehicle is a 2024+ model, connect your bench cable at this time. Follow the instructions for the bench cable installation here.

Step 3: Write the VIN

  1. Navigate to Settings: On the EK1 device, go to the Settings and Gauge Info screen.
  2. Select "Writing VIN": Choose the "Writing VIN" option from the menu.
  3. Choose the VIN File: When prompted, select the VIN file from the INIT folder on the SD card.
  4. Confirm the VIN: The VIN will now be written to the new ECU. Note: This step can only be performed once, so double-check that you have provided the correct VIN.

Step 4: Start the Car

  1. Crank the Engine: Try starting the car. It may take a few attempts before it starts.
  2. Remove the Bench Cable (2024+ Models Only): If you used a bench cable for a 2024+ vehicle, disconnect it before trying to start the car. Reattach all original connectors.

Step 5: Final Steps

  • You are now ready to use your spare ECU: The ECU is fully installed and paired with your vehicle.
  • Optional: You can proceed with patching or tuning the ECU as needed.