Problems With T180 Keyless \ Smart Entry

[kammy1975]

Hi all

Looking for some wisdom here. Wife told me on friday that she had spotted the RAV4 telling her that the Battery was low on the keyfob, so planning ahead I ordered one off eBay (a Panasonic) and sure enough, the remote fob stopped working yesterday. So fitted the new Battery, but the car seems to not be responding at all well to the fob. Tried the new Battery in the second fob, and same odd behaviour.

So got down to B & Q and got myself an Energizer battery to eliminate the fact it could be battery related, and the same behaviour still. Basically, the car unlocks eventually, but takes numerous attempts before unlocking, and is even harder to get it to lock. What makes it worse is that the buttons on the remote refuse to work at all, on both remotes, with 2 different new batteries.

Have noticed that there is a red led that glows on the key fob when you bring it near the car, and it seems to flicker on and off as you try to unlock it, but it isnt behaving well at all.

Any ideas ? Batteries were cleaned before installing, and I ensured I didnt touch the two poles (if thats the right term!) I can only assume that there is something wrong with the actual control unit in the vehicle, but the other bizarre thing is that my electric garage remote has stppped working. Could this be due to something transmitting radio frequencies in my area? (read this in another post) Would find that odd in itself, as I am at the end of a cul-de-sac with no neighbours behind my house for at least 500metres...

[Nerfie]

Coincidently I had a very similar issue with my Yaris.

The car refused to open on touch, or keyfob. Went to get the spare, but it started working again! took the spare anyway and left the original one to get the Battery changed, however, the spare then started to act up! When I went back to get the original, the spare started working again... bare with me...

I then had the Battery replaced, on the original, and it still was a little dickie, but it's now been fine. apart from once at ASDA it refused to open again, same issues as the ones you've described.

Anyway, spoke to Toyota briefly, they think the keys might just need reprogramming or something (someone spoke to them on my behalf I should say) but they said it wouldn't be a problem to do etc and just let them know when I want it done.

:0

Strange issue indeed, but it's cleared up by itself. I blame climate change /snigger.

[shcm]

OK,

First, to remove any doubt, get a voltmeter across the terminals of the fob Battery. A fresh Battery will usually be a little above 3V (about 3.1V), off load, removed from the fob.

Second, sometimes it can be helpful to press a button (and possibly holding it down for a few seconds) with the Battery removed. This may help discharge any capacitors across the power supply. When the battery is removed, because these things draw very little current when idle, the voltage on the capacitor(s) can take a while to decay. As the voltage droops slowly, the digital bits (i.e. usually a small microcontroller) can get themselves into, (lets say for simplicity), a strange state. They then need a hard reset. This usually occurs when the voltage comes up, but because the voltage hasn't dropped far enough anyway (the capacitors are still charged), they don't get a reset. The button press may draw a fair bit more current, helping to discharge the capacitor fully, or at least below the threshold, where a reset will occur when the battery is re-inserted. Hopefully that won't cause a re-sync problem though.

When you approach the vehicle, you should get a single red led flash from the fob and you should notice the interior lights come on. This is a good indication that the car is hearing the transmission from the fob. Before you touch the handle, you should continue to get a single red led flash from the fob every 4 to 5 seconds, while you are close to the vehicle.

You should also get a single red flash from the fob if you press the lock or unlock buttons.

I take it that once in the vehicle, you are not having any problems starting it? If my understanding of the system is correct,

normally the radio link (UHF) is also used for starting and the transponder link (LF - 125 kHz), is only used as a backup if the fob battery has failed. This is the situation when you have to hold the fob close to the start button.

When locking/unlocking with the fob buttons (not touching the handle), do you have to get very close before it works?

The fact that the garage door opener is having problems, could be an indication that something else has popped up in the band near you. Unfortunately, it is an unlicensed bit of spectrum.

Do you have the same problem wherever the vehicle is, or just at your house?

Have you bought any new electrical stuff recently? Put up any high intensity lighting? (I know that may sound crazy, but just stay with me).

Cheers

[MarsKy]

Hi all

Looking for some wisdom here. Wife told me on friday that she had spotted the RAV4 telling her that the battery was low on the keyfob, so planning ahead I ordered one off eBay (a Panasonic) and sure enough, the remote fob stopped working yesterday. So fitted the new battery, but the car seems to not be responding at all well to the fob. Tried the new battery in the second fob, and same odd behaviour.

So got down to B & Q and got myself an Energizer battery to eliminate the fact it could be battery related, and the same behaviour still. Basically, the car unlocks eventually, but takes numerous attempts before unlocking, and is even harder to get it to lock. What makes it worse is that the buttons on the remote refuse to work at all, on both remotes, with 2 different new batteries.

Have noticed that there is a red led that glows on the key fob when you bring it near the car, and it seems to flicker on and off as you try to unlock it, but it isnt behaving well at all.

Any ideas ? Batteries were cleaned before installing, and I ensured I didnt touch the two poles (if thats the right term!) I can only assume that there is something wrong with the actual control unit in the vehicle, but the other bizarre thing is that my electric garage remote has stppped working. Could this be due to something transmitting radio frequencies in my area? (read this in another post) Would find that odd in itself, as I am at the end of a cul-de-sac with no neighbours behind my house for at least 500metres...

My T180's driver door wouldn't unlock properly on touching the handle. It would click as if attempting to unlock, but wouldn't do it. For its 2nd year service the dealer offered to replace the batteries as part of the service. But all they did was leave the batteries. Then the low fob Battery warning started coming on soon after. So fitted the new batteries and the unlocking problem has gone away.

[kammy1975]

Hi all,

Thanks for the posts and info.

Interesting turn of events. Tried the original fob, with the new Battery today, and it worked when using the handle to lock\unlock the vehicle. Car started fine also. Drove to the supermarket and on route the in dash LCD reported key not detected, so I quickly put the key next to the start\stop button, and the message cleared. On arrival at the supermarket, I sent the wife in, whilst I had a play with the fob. Bizarrely everything now worked perfectly fine, except the range of the fob when using the buttons was no more than 10ft away. Got back home, and parked car in its usual spot, and the fob worked as normal, but again the range of the fob when using the buttons has been reduced to what it used to be.

Just took the Battery out, and can confirm it is reporting 3.08v on a voltmeter, so defo eliminates that. Annoyingly I was quick to throw away the old batteries, so cant test them to see if they were genuinely low.

Anything I can do to improve the range of the fob when using the buttons?

shcm - The odd thing I have noticed is that when the fob had the issue, rather than blinking every 4 to5 seconds as you describe, it would flash like crazy when stood next to the car, and putting your hand inside the door handle to trigger the unlock of the doors. Is there some learning process that goes on after a change of Battery?

Thanks

Kam

OK,

First, to remove any doubt, get a voltmeter across the terminals of the fob battery. A fresh battery will usually be a little above 3V (about 3.1V), off load, removed from the fob.

Second, sometimes it can be helpful to press a button (and possibly holding it down for a few seconds) with the battery removed. This may help discharge any capacitors across the power supply. When the battery is removed, because these things draw very little current when idle, the voltage on the capacitor(s) can take a while to decay. As the voltage droops slowly, the digital bits (i.e. usually a small microcontroller) can get themselves into, (lets say for simplicity), a strange state. They then need a hard reset. This usually occurs when the voltage comes up, but because the voltage hasn't dropped far enough anyway (the capacitors are still charged), they don't get a reset. The button press may draw a fair bit more current, helping to discharge the capacitor fully, or at least below the threshold, where a reset will occur when the battery is re-inserted. Hopefully that won't cause a re-sync problem though.

When you approach the vehicle, you should get a single red led flash from the fob and you should notice the interior lights come on. This is a good indication that the car is hearing the transmission from the fob. Before you touch the handle, you should continue to get a single red led flash from the fob every 4 to 5 seconds, while you are close to the vehicle.

You should also get a single red flash from the fob if you press the lock or unlock buttons.

I take it that once in the vehicle, you are not having any problems starting it? If my understanding of the system is correct,

normally the radio link (UHF) is also used for starting and the transponder link (LF - 125 kHz), is only used as a backup if the fob battery has failed. This is the situation when you have to hold the fob close to the start button.

When locking/unlocking with the fob buttons (not touching the handle), do you have to get very close before it works?

The fact that the garage door opener is having problems, could be an indication that something else has popped up in the band near you. Unfortunately, it is an unlicensed bit of spectrum.

Do you have the same problem wherever the vehicle is, or just at your house?

Have you bought any new electrical stuff recently? Put up any high intensity lighting? (I know that may sound crazy, but just stay with me).

Cheers

[Nerfie]

the range was dented on mine, but again, it's cleared its self up.

I'm not sure why, nothing changed, and it happened in different locations.

Btw, I do have Keyless entry as well. :P

[shcm]

shcm - The odd thing I have noticed is that when the fob had the issue, rather than blinking every 4 to5 seconds as you describe, it would flash like crazy when stood next to the car, and putting your hand inside the door handle to trigger the unlock of the doors. Is there some learning process that goes on after a change of battery?

Would you say the blinking rate was about 4 times a second?

My understanding is, before the fob gets close to the car and the car hears the fob, the car is sending an activitation signal every 250ms (4 times a second). When the fob hears this activation signal, it replies to the car. If the car hears the response from the fob, the rate of signals sent from the car would appear to drop.

So, it would seem reasonable that, if the fob is hearing all the activation signals from the car, but the car is not hearing the fob, the car will continue to send the activiation signals 4 times a second and the fob will respond to each one. That would produce much more rapid flashing of the LED. If the interior lights are not turning on in the car as you approach, that would appear to support the above. If they do turn on, then I'm wrong.

It does sound like the UHF receiver has gone deaf, or is being de-sensitised (blocked) by something. The fact that both fobs cause the same effect and the fact that the car is not hearing the fob when it is in the vehicle (your "key not detected" message - the car still uses the UHF receiver to get responses from the fob in this case), would sort of support this, with the facts available. I suppose a certification (security) ECU or odd harness fault is also a possibility.

If it is happening in multiple locations, but you are not travelling very far, then it's possible it's a relatively high power transmitter somewhere, but I would expect a whole load of other people having problems with their remote locking, not just you. It's also possible something you are carrying around, or have fitted to the vehicle is causing it, but you'd expect it to be something that has changed recently.

The UHF receiver is on the driver's side between C and D pillars (boot side window area). There is the old trick of holding the fob higher or holding it under your chin, which can boost the range.

I can't remember if there is a manual re-syncing or learning process with this system. I will have to RTFM.

As Nerfie says, maybe it will just clear up. If, for example, the local oscillator in the receiver drifts for some reason, that would cause it to appear de-sensitised as well. Sorry, probably too technical now.

[vivianM]

Hi all

Looking for some wisdom here. Wife told me on friday that she had spotted the RAV4 telling her that the battery was low on the keyfob, so planning ahead I ordered one off eBay (a Panasonic) and sure enough, the remote fob stopped working yesterday. So fitted the new battery, but the car seems to not be responding at all well to the fob. Tried the new battery in the second fob, and same odd behaviour.

So got down to B & Q and got myself an Energizer battery to eliminate the fact it could be battery related, and the same behaviour still. Basically, the car unlocks eventually, but takes numerous attempts before unlocking, and is even harder to get it to lock. What makes it worse is that the buttons on the remote refuse to work at all, on both remotes, with 2 different new batteries.

Have noticed that there is a red led that glows on the key fob when you bring it near the car, and it seems to flicker on and off as you try to unlock it, but it isnt behaving well at all.

Any ideas ? Batteries were cleaned before installing, and I ensured I didnt touch the two poles (if thats the right term!) I can only assume that there is something wrong with the actual control unit in the vehicle, but the other bizarre thing is that my electric garage remote has stppped working. Could this be due to something transmitting radio frequencies in my area? (read this in another post) Would find that odd in itself, as I am at the end of a cul-de-sac with no neighbours behind my house for at least 500metres...

Hi Kammy,

I did have a similar problem in that I could not get in the T180 and had to get my wife to bring out the spare key - even when I got in the original key would not start the engine - my Toyota dealer fitted new batteries to both keys and all has been ok since. Maybe it takes some time for new batteries to settle down in the key - There have been endless problems with imobilisers when cars are parked at a local hospital !

PS Been round N Wales (with spare in boot, 2 passengers and luggage) average OBC 37.2 MPG - back to 36.6 on trip to Sheffield this morning.

Best wishes

Bet your brakes are well bedded in now!

Guy

[Nerfie]

Good info that shcm,

might explain a lot! It was happening distance locations in my case. I'll mention that when I get around to take it to Toyota, prolly when the service is due :)