Prius smart key trunk unlock button not working.

Remove the inner hatch panel to expose the wiring on the switch. Make sure everything is connected and not corroded or loose

 

This could be as simple as spraying WD 40 on the hatch actuator. I'm not sure why the SKS button on the hatch doesn't work though. I would probably first just spray the hatch "latch" and open and close it a few times. If that doesn't work, remove the hatch panel and spray the lock actuator and any other moving mechanical parts of the latch. If that doesn't fix it, check all connections for corrosion.

 

My idea is that the Smart system receiver located behind the rear bumper has failed or the associated wiring harness connector has a problem. Hence the system fails to recognize an authorized fob is in the vicinity and the hatch therefore will not unlock.

 

It is a pain. Try this first
Have someone stand right at the drivers door with the key fob in their pocket or person, then you go to the hatch and try to open it or press down the button and see if the doors lock.

 

No.

It is located in the hatch floor near the rear bumper. You may have to pull off the plastic trim that lines the hatch opening for access. The official name of this part is "luggage electrical key oscillator (outer)". There is also an "electrical key antenna (rear)" nearby.

As you remove the folding hatch floor and the large black plastic tray over the spare tire, you will see the luggage electrical key oscillator (inner) near the traction battery, on the left. That is not the part in question.

The Prius Smart system has five of these electrical key oscillators: one in each front door, one in front of the rear bumper, one near the traction battery and the last near the center console between the front seats. This is how the Smart ECU can determine whether the fob is inside or outside the car and if outside, which door/hatch should be allowed to be unlocked.

It needs to know whether the fob is inside or outside because certain functions are not allowed depending upon where the fob is located. As one example, if the fob is determined to be inside the car, the locking system will not allow the driver to lock the car by pressing one of the little square black buttons on the car's exterior.

As another example, if the fob is determined to be on the outside of the car near the driver's door, only that door can be unlocked (when in default mode).

 

Hy, i had the same problem and i solved it by replacing o rod pin from the plug that connects to the luggage electronic key os ccilator that is placed in the trunk, in front of the rear bumper. I upload a picture with that plug:



For me was a succes story, because of you all that write on this site. Thanks for all your guidance

 

P.S. The pin wasn't only rod but even broken probably due to the vibrations and rustiiness condition it were.

 

Sorry this post might be old one, but i have challenge on 08 Prius where only the smart key is not working but lock and unlock.
The fob button are working perfect.