10/01/2025 03:06:07

Car Computer - HW2.5 to HW3 (Retrofit)

Correction code 21153206 1.62 NOTE: Unless otherwise explicitly stated in the procedure, the above correction code and FRT reflect all of the work required to perform this procedure, including the linked procedures. Do not stack correction codes unless explicitly told to do so. NOTE: See Flat Rate Times to learn more about FRTs and how they are created. To provide feedback on FRT values, email LaborTimeFeedback@tesla.com. NOTE: See Personal Protection to make sure wearing proper PPE when performing the below procedure.

Parts that may be required for this procedure:
  • 1565697-00-A M3,HW3 RETROFIT,SPLICED WIRES
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Note
See section below to determine whether the part may be required for the retrofit.
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Note
Determining the vehicle build date is only required for Fremont built Model 3 vehicles (VIN starting with 5YJ). All Model 3 vehicles built at Giga Shanghai are built after August 2018.

Confirm Vehicle Build Date and Additional Parts Required (Fremont Built Vehicles Only)

  1. Connect a laptop with Toolbox 3 to the vehicle. See Toolbox 3 (Connect and Disconnect).
  2. In Toolbox, select Dashboards > Service Tools > Vitals, and then type " bday" into the search field.
    • If the vehicle's Birth Date is August 1, 2018 or later, no wiring rework is required.
    • If the vehicle's Birth Date is before August 1, 2018, wiring rework may be required. Use the part number shown at the top of this procedure.
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    Note
    Do not yet disconnect the laptop from the vehicle.

Prepare for Retrofit HW3 Car Computer

  1. For Third Party repairs only: perform the Toolbox Owner Authorization Request.
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    Note
    If the repair was booked through Tesla Service, the customer has already given authorization. Go to the next step.
    1. Log in to https://toolbox.tesla.com/help/owner_authorization.
    2. On the left panel, click Owner Authorization Request, and then click Request Owner Authorization in the main panel.
    3. Complete and submit the form.
    4. Ask the vehicle owner to approve the authorization request that was sent to their email.
  2. Click on Dashboards > Car Computer Replacement and on the "Getting Started" page, click on Next Step.
  3. On the "Backup & Factory Reset" page, click Next Step and follow the prompts to perform a profile backup and factory reset on the car computer.
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    Note
    The car computer will reboot several times during this step.
  4. Once the "Replace" page appears, the car computer can be replaced.

Retrofit HW3 Car Computer

  1. Use the instructions in the appropriate "Remove and Install" procedure to replace the car computer:
    Select the appropriate Car Computer (Remove and Install) procedure:
    Perform the following tasks that are described in the (Remove and Install) procedure:
    1. Remove the current car computer.
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      Note
      If the vehicle's build date as determined earlier is before August 1, 2018, first perform the electrical wiring rework that may be required before continuing to the next steps. See Electrical Wiring Rework.
    2. Fasten the replacement car computer to the vehicle and connect all harnesses and hoses to the computer.
    3. Prepare the vehicle for a Coolant Air Purge.
    4. If it was released, reinstall the front passenger airbag.
    5. If the car computer ground strap was released from the vehicle, install it back on the vehicle.
    6. Install the front passenger knee airbag and any air ducts that were removed.
    7. Reconnect 12V/LV power. See 12V/LV Power (Disconnect and Connect).
    8. Connect an LV maintainer to the vehicle, but do not disconnect the LV battery. See LV Maintainer (Connect and Disconnect).
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      Note
      On 12V lead acid batteries, connect the 12V maintainer to the lead acid battery terminals.
    9. Perform the Coolant Air Purge routine. See Cooling System (Partial Refill and Bleed).
  2. Reestablish the Toolbox laptop connection, and in the "Replace" page, click Next Step to go to the "Associate" page.
  3. Follow the prompts to transfer configs and associate the replacement car computer.
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    Note
    The car computer will reboot several times.
  4. When association is complete and the VIN is confirmed online, click Next Step to go to the "Update" page.
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    Note
    If necessary, Reconnect the Toolbox connection.
  5. Click Start Part Replacement OTA to deploy a software update to the vehicle.
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    Note
    If necessary, Reconnect the Toolbox connection.
  6. Use the vehicle touchscreen to install the software package. See Software Reinstall - Touchscreen.
  7. In Toolbox, click Next Page to go to the "Restore" page, and then follow the prompts to restore the vehicle profile.
  8. Disconnect the laptop from the vehicle.
  9. Install any remaining components that were removed.
    Select the appropriate Car Computer (Remove and Install) procedure:
  10. Make sure to properly dispose of the old car computer. Follow the instructions in Car Computer (Dispose) and add correction code 21151007 as a separate activity to the Service Visit.

Electrical Wiring Rework

This procedure may only required on vehicles built before August 1, 2018 and only applies to Model 3 vehicles built at Fremont (VIN starting with 5YJ).
  1. Locate connector X121 on the car computer harness and check whether connector pins 5 and 13 are populated with wires.
    • If pins 5 and 13 are populated with wires, go to step 1.b in the “Retrofit HW3 Car Computer” section of this document.
    • If pins 5 and 13 are empty, go to the next step.
    Figure 1. Location of connector X121 at car computer side
    Figure 2. Connector X121 (male side shown)
    Figure 3. Connector X121 pin 5 and 13 wire population
  2. Remove the glove box. See Glove Box - Without Knee Airbags (Remove and Replace) or Glove Box - With Knee Airbags (Non-Heat Pump) (Remove and Replace).
  3. Cut the black wire in pin 15 and the white wire in pin 4 of electrical connector X121 using diagonal cutters.
  4. Completely wrap the end of the black wire from cavity 15 using yellow electrical tape from the wire harness repair kit.
  5. Strip and then twist the end of the white wire that came from pin 4 of electrical connector X121.
  6. Slide approximately 5 cm (2 in) of heat shrink tubing over the stripped white wire and move it away from the exposed wiring. The tubing will later be used to protect the wire splice.
  7. Position the crimp barrel on the stripped white wire, and then crimp the crimp barrel on the white wire.
  8. Position the crimp barrel on the wire splice, and then crimp the barrel on the wire splice.
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    Note
    Wire splice colors may vary from those shown in the picture.
  9. Spot solder both sides of the crimp barrel.
  10. Slide the heat shrink tubing over the crimp barrel, and then seal the heat shrink to a water-tight fit using a heat gun.
  11. Lift the terminal position assurance retainer of electrical connector X121 using a small flat head screwdriver.
  12. Insert the pins from the wire splice into pin locations 5 and 13 of electrical connector X121, and then close the terminal position assurance retainer.
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    Note
    Wire splice colors may vary from those shown in the picture.
  13. Wrap the wires of electrical connector X121 with yellow electrical tape to indicate that the electrical rework has been completed.
  14. Return to step 1.b in the "Retrofit HW3 Car Computer" section to complete installation of the new car computer.