Electric Frunk (Mark 4.X)
This is the installation guide for Tesla Model 3 (2021+) Electric Frunk (Mark 4.X) from Tesla Offer.


Touch Screen
Tesla Official App
Key Fob


Height Setting

Adjust the liftgate to your desired height. Press and hold the button on the ECU for about 5 seconds, until you hear a beep (Make sure the buzzer is connected).

Speed Setting

When the frunk is in open state, press and hold the button on the control unit. You will eventually hear two long beeps (speed 2), three long beeps (speed 3), four long beeps (speed 4), up to six long beeps (speed 6). Release the button after you hear the speed you want to set. The slowest speed is speed 2 and the highest speed is speed 6. The factory default is at speed 4.

Packing List

    Lock Assembly with Latch Motor
    Replacement Strut x 2
    Struts Backplate (L and R)
    3M Tape
    Cable ties
    ECU Unit
    Signal Wire Harness
    Fuse Cable
    ECU Wire Harness


    10mm Hex Socket
    13mm Hex Socket
    Small Flat Head Screwdriver
    Pry Tool
    Electrical Tape


Step 1 - Removing Trim Pieces

Remove the cover panel piece on the top of the frunk. Pull it out with bare hand. Then remove the air inlet piece as shown in picture.

Step 2 - Detaching Button and Spring

Pull out the small cover on the front of the frunk. Then unplug the wire from the emergency button. You can also remove the spring from the latch now.
Pull out the cover
Unplug the wire
Remove the spring. You can simply use a hand to force the spring to one side and release the hook.

Step 3 - Removing the Frunk Well

There are 7 10mm hex screws as indicated. Remove all of them. Then you can pull out the frunk tray.

Step 4 - Replacing the Struts

Now we will remove the struts. Let's start with the left side of the car. Insert a flathead screwdriver into the channel as shown in the picture, and then with one hand pushing up the hood a bit, pull the strut out.
Repeat the same thing to the lower ball joint.
Now the hood might fall so be caution. On the top joint, use a 13mm hex socket to remove the screws to remove the OEM back plate. Replace it with our back plate marked "L" (Note: The two back plate we provided are different. One has a "R" on it and one has a "L" on it. Use the "L" on the left side of the car. )
Replace the backplate with our plate that is marked "L"
Tighten the screws again
Insert one of our strut into the lower joint (the side of the strut that near the wire). Don't insert it to the upper joint yet, because it will make it more difficult to remove the right strut.
insert the strut into the lower joint.
Now go ahead and remove the right strut from the upper joint. After you remove the upper joint of the right OEM strut, the hood will be completely freed, so use a hand to support the hood. Now go back to the left side of the car and mount the left strut to the upper joint.
Remove the right OEM strut completely, then do the same thing as you did to the left side of the car (swap the backplate, and mount the right strut)
The struts are successfully installed. Run the wires beneath the trim piece to the location where the battery is located, and then attach the connectors to the major wire harness.
Connect the connector pair from each strut to the major wire harness.

Step 5 - Adding Latching Mechanism

Remove the 10mm hex screws as indicated in the picture
Hook our latching mechanism plate (the big black one attached on our latch wire) to the indicated hole, and the put back the removed 10mm hex screw. Now on the small little black metal, insert the plate into the green location by the hole indicated as blue.
Now hook the spring provided by us.
Hook the spring provided by us

Step 6 - Connecting the signal wire

Now take out the signal wire. There are two connector pairs.
Unplug the OEM connector from the lock motor that is located on the left side of your car (if you are facing toward the car it's on your right side)
Connect one side of our blue connector pair to the removed OEM connector, and plug the other side of our blue connector back into the lock motor.
Now remove the OEM plug from the latching lock. Plug the OEM plug to one side of our corresponding connector pair, and the other side of our corresponding connector pair back to the latching lock. Make sure they are fully inserted.
the other connector pair
Unplug the OEM connector from the latching lock
After connector pair is connected
On the other side of the signal wire, connect the black little connector to the 4pin connector from the major wire harness.
Now connect the brown connector from the major wire harness to the latch motor, and fix the latch motor by cable tie.
Tie the latch motor here. There's two hole, one hole is smaller so use the thinner cable tie.
Attach the brown connector from the wire bundle to the latch motor

Step 7 - Connecting the power and ground

Get the small black wire that come with the fuse. Insect the metal end into the positive terminal of the 12V battery. You need to use a 10mm hex socket to loosen the terminal and insert the metal below the metal nut, and then tighten it again.
Loosen the 10mm nut from positive terminal
Insert the fork crimp into the positive terminal, tighten the nut
On the other side of the fuse wire, unplug the white plug, and connect the silver terminal from the major wire harness to the plug, then connect it back to the fuse wire.
Unplug the white plug
Insert the silver terminal into the white plug as indicated, make sure it is fully inserted and locked
Connect the white plugs together again
Wrap the white connections and the fuse box with electrical tape
Connect the ground (the golden spade terminal that come with the wire harness) to the indicated location, it's in the left side of the car, under a 10mm hex nut.
Ground connection

Step 8 - Finishing up

Connect the buzzer to the major wire harness by the 2pin connector
Connect the big plug from the major wire harness to the waterproof control unit.
push in and release the lock of the plug
Insert the plug into the control unit, and the rotate the plug handle to lock the plug.
The light on the control unit
If you have the homelink module (optional feature), then you can plug it into this connector, and then wrap the homelink module with electrical tape then set it beside the 12V battery.

Step 9 - Testing the system

Now the system is ready to be tested. We need to make sure the latch can be released after locking, so use your hand or a screwdriver, push downward on the latch to "lock" the latch. Then plug in the OEM wire back to the emergency button (On the little cover that you removed). Press the emergency button to make sure the latch release.
If the latch release, then the system is ready to be tested. Hold the black button on the control unit until you hear a beep to initialize the system. After initialize, press the emergency button to test the frunk closing. If the frunk close successfully, then go to open the frunk from the touchscreen to test the opening.

Software Update

GitHub - evoffer/electric-liftgate-firmware: Firmware Update for Tesla Electric Liftgate Systems (Model S/X/3) from Tesla Offer

Step 1 - Preparing Memory Card

Prepare a microSD with 32GB or below capacity. Make sure it is in FAT32 format.

Step 2 - Getting the Update File

Get the update file ready. The file would be provided by tech support if needed. Rename the file to update.yst and place it under the root of the microSD.
Eject it from the card reader afterwards.

Step 3 - Flashing the Update

Insert the microSD into the control unit. The red LED will be flashing rapidly.
Wait until the LED becomes solid and eject the microSD.

Complete! Test the System

The LED should be flashing constantly now and you are all set!
Last modified 5mo ago