How I Fixed my Broken Toyota Prius Remote Key Fob

When I bought my Prius from Hodgsons Toyota in Gateshead last year I remember asking if there were two keys with the car.  I had, after all, been stung by this in the past and I had no wish to once again own a car with only one key.  Yes, came the answer, there were indeed two keys.  Good I said.  Later, once I got the car home I said something different.  I won't repeat it.  Not on this blog.  One of the two remote key fobs was not working.  I could lock the car with it, and drive the car with it, but I could not unlock the car with it.  Naughty them.  As a used approved Toyota, one would expect every aspect of my car to have been inspected and checked, including the key.  You cannot, after all, use a car without one.  Perhaps keys just don't feature in their checklists.  I'd love to know if others have had a similar experience, or indeed if anyone knows of manufacturers who include inspection of keys as a standard checklist item for a used approved vehicle.  Please leave a comment below if you have any stories.  I am sure others as well as myself would love to read of such experiences.

Right, back to my poor wee broken Prius key fob.  Something didn't feel right with the unlock button, in a tactile sense I mean.  It was as if something had been knocked out of place within the inner mechanism of the button.  I didn't know anything about the structure of the key fob.  Google is my friend, however, and after a little digging about on the web I figured out a plan. Now it is worth mentioning that my remote key fob is not a smart (SKS) type - just the plain old standard key fob.  I am sure the technique I used will be good for both.  Without further ado, here is what I did.

• I got a scalpel knife, like the one shown below.  Make sure the blade is as razor sharp as possible in order to get as clean and neat a cut as you can.

• Put the remote key fob on a hard flat surface with some protection in place.  You don't want to damage a table if the knife blade slips.
• Make a cut with the knife as shown in the photo below.  This is just to break the seal between the rubber membrane and the hard plastic case.  Note: it was the unlock button on my key I was fixing.

• With just enough of the rubber membrane cut neatly along the seal between it and the hard plastic case, peel back the rubber membrane to expose the inner button mechanism.  Each button has a hard white plastic microswitch - square in shape - fixed onto the circuit board.  There is a circular 'plunger' at the centre of each microswitch.  On my key, it was this that had been knocked out of alignment with its recess in the rubber membrane above.  Gently tease the circular plunger back into alignment using your finger or tweezers.  Test that the circular plunger by pushing it down.  It should click. (You might even wish to test it by carefully taking it near to your Prius and checking if the door unlocks.)
• Now you are sure the unlock microswitch is working, carefully replace the rubber membrane.  Ensure the recess within the rubber membrane covers the circular plunger of the microswitch correctly.
• Lastly, apply some Loctite / Superglue to the edge of the rubber membrane and the plastic casing and glue together.  Keep fastened in place while the glue cures by applying masking tape or equivalent.
• Congratulations!  Your key should be fixed and ready to use.

I now have a fully working remote key fob and it was fixed with standard household items.  It has never come apart and always works when I use it.  Incidentally, it was the same key that I used to take the photo above.

­Lost My Prius Remote Key Fob - And Found It Again

Agh! I lost my master Prius remote key fob the other day.  I'd had a hectic day organising childcare then driving a hired van to take some of our household furniture and items into storage as part of a de-cluttering exercise.  Stupidly, I had the van keys, the Prius key and our second car's key in my boiler suit pocket altogether.  These got swapped at different points in the day's activities between my rucksack and boiler suit.  With the hire van outside the next morning and due to be taken back to the depot I was searching the house high and low for my Prius keys.  Slowly, that sinking feeling that I had lost the Prius keys started to sink in.  It wasn't just the fact that this was the master key that was upsetting me so much as the fact that my house keys and other important keys were on the same key ring.  I grabbed the second Prius remote fob and used that with my back door key so that I could get the van back and get other jobs out of the way.  I'd look again later, I thought.

Well, later came and it fared no better.  I'd already thoroughly checked the van to see I hadn't dropped the keys in the cab.  I called my wife on her mobile phone and left a message - had she seen them?  I was starting to get agitated so I called the van rental company to see if maybe the keys had slid out of my pocket and got wedged between the driver's seat and backrest.  They were very obliging and as helpful as they could be but, nope, no joy either.

A Possible Solution to Replacing the Lost Prius Key

I then started to check the internet for solutions.  Well, where else do you turn to for help in the 21st Century?  I came across useful devices that you can attach to your key fob that help you locate them when lost, such as the Loc8tor Lite that you can buy from online stores like Amazon (click here to see more info). However, these devices are not for those blessed with after-thoughts like myself.  I then turned to thinking of buying a second hand Prius remote key fob from eBay where a search of completed listings shows that you can pick one up for around £30 to £35 plus shipping (about another £2 to £3).  'Aha!' I thought.  All I need do now is learn what the options are for programming it for my car.  The most obvious, and most expensive option, would be to get the remote programmed at my local Toyota dealership.  The second option would be to try programming the key myself.  A quick internet search turns up possible solutions, such as the one below that should match the needs of my second generation 2006 Prius.  Please note: I did not try this sequence myself so I cannot vouch for its effectiveness or accuracy.  (If anyone has tried it then I’d love to hear from you and you could help others too.)

Reprogramming sequence:

STEP 1. Driver door open, no key in slot, door unlocked. 
STEP 2. Put valid key in and out of slot twice within 5 seconds. 
STEP 3. Close and open driver door twice. 
STEP 4. Insert and remove key in slot. 
STEP 5. Close and open driver door twice. 
STEP 6. Insert master key in slot and close door. 
STEP 7. Press power on then press power off in one second interval. This is add mode 
STEP 8. Remove key from slot 
STEP 9. Car should lock and unlock door once for add mode. 
STEP 10. Press both buttons on transmitter. 
STEP 11. Within 3 seconds, press one button. 
STEP 12. Car should respond with one lock-unlock. Two means it didn't work. 
STEP 13. Open a door or put key in slot. 

Problem Solved

How did I eventually solve the problem?  My wife called back.  Yes, she had the key all along.  Didn’t I know that? I wasn’t sure whether to rage or punch the air for joy.  Joy won over in a flash.  I was pretty darned happy actually.  Relieved too.  Lessons to be learned up here?  Don’t put all your important keys on one bunch.  Consider buying a key finder gadget like the one mentioned above.  Communicate with your darling spouse.  Some of these lessons will no doubt be easier to implement than others.

In the meantime, happy driving!