Door Key

[MLW2233]

Today the door key/modum would not look the car. As the Battery is about 3.5 years old, I assume it needs replacing. Have seen the guide in the car manual, but I was wondering are there any pitfalls to doing a straight Battery swap?

[alan333]

Haven't done one on a Prius but the Avensis one has no pitfalls that I encountered. Some keyfobs (maybe not the Toyota ones tho) can lose their code if the Battery is out for a while, so I always try to do them quickly, ie within a minute or so. Just make sure you have the correct Battery before you start, and follow the instruction book.

[Grumpy Cabbie]

Mine gets changed every 2 years with the major service at the dealers. It's a case of opening the back and swapping old with new Battery. Dead easy.

You might want to consider changing the Battery in your 2nd key fob too just in case.

[MLW2233]

Thanks, for those comments. It looks easy. I planned to do my fob, wait a week till all is well, and then do the other. Is 2 years a fair lifespan for a Battery?

Just a note, faced with not being able to lock the car, I pressed the internal door lock with the drivers door open. Everything locked bar the drivers door which I then locked with the mechanical key. It woorked fine and saved the day. When I returned the fob actually opened it normally. I assume the Battery has 'rested' and had enough juice to operate.

[Grumpy Cabbie]

I replaced the Battery in my 2nd/spare fob this year as it was totally flat. It worked about 6 months ago when I checked (and the car was 4.5 years old then). So 3.5 years seems a good innings for them. I guess it depends on where you keep them and the use of your car etc. I walk past my car a few times a day without getting in it, but the car will communicate with the fab every time (causing the interior lights to come on for a few seconds).

You might be able to get 3 years out of a fob Battery but the replacements are so cheap that I just do it every major service. Once you know it's an easy fix it'll stop any worries or concerns in the future, esp if you have your spare key just in case.

[korat102]

ok, forget my post lol

I saw Battery change and assumed it was the 12v Battery. Must read proper like...

[JSHarris]

The fob Battery is easy to change as a diy job, as, rather thoughtfully, Toyota have made the end of the emergency key just the right shape to open the fob by twisting it in the small hidden slot. The procedure is to remove the emergency key from the fob, which then reveals a small slot. Fit the end of the emergency key in this slot, twist gently and the fob pops open.

[Grumpy Cabbie]

The fob battery is easy to change as a diy job, as, rather thoughtfully, Toyota have made the end of the emergency key just the right shape to open the fob by twisting it in the small hidden slot. The procedure is to remove the emergency key from the fob, which then reveals a small slot. Fit the end of the emergency key in this slot, twist gently and the fob pops open.

You know we're all going to run off and try this now :)

[MLW2233]

One thing I was thinking of, if I locked the car and double clicked it to set the alarm etc, and when I returned the fob would not work (flat battery), what then?

I thoght open the door mechanically with the key. The alarm will go off, but when the fob is put in the dashboard the alarm etc should go out as the car recognizes that it is you. Then start as normal.

Is this correct?

[Grumpy Cabbie]

Yes

You have to hold it to the little blanked out 'button' space under the Start/On button. Or at least it's there on the gen3. I believe a very similar system is on the gen2. You have to hold it right against it though.

[PeteB]

On the Gen 2 you insert the key into the key slot, and press Start - the alarm stops once the car enters 'Ready' Mode.

You have to do the same rigmarole on the Gen 2 if the car's 12V Battery has been flat. Once you restore power (i.e. connect jump leads or a jump starter) the alarm will probably go off, and starting the car is the way to stop it.

[MLW2233]

UPDATE

Got a pack of batteries from a one pound shop. Replacing the Battery was very easy about 2-3 minutes. The 4 Phillips screws are very small so get a good small screwdriver. I had a good one from Maplins. The screws are easy to get out as they screw into brass threads, all very high quality. There is a rubber seal that is a rubber ring a tiny bit bigger than the Battery size. Make sure this is located in the indentation located around the Battery.

Next time I'll do it every 2 years to avoid the panic of no locking.