Member Since: 17 Jun 2008
Location: widnes, cheshire
Posts: 117
both key fobs not working - help
Hi guys,
i have an 05 plate disco 3, a year ago one of my key fobs stopped working. I was lazy and never done anything about it. i just used my spare key. But now my spare key has also stopped working. dont get me wrong, both keys will start the engine but both will not open or lock the doors. I had the fisrt key looked at by LR and they told me I needed a new key at the cost of £150.00. I cant believe the other key is now also broke.
it states in the LR manual that the battery in these fobs is none replacable but should last for 10years. The car is only 4 years old.
can someone tell me exactly how the car ignition charges this battery up?? is there a way of leaving the key in the ignition for t to charge?? or does someone know if i can open up the fob and replace the battery mself as i am quite handy??
or does anyone think if i complain to LRCC stating that there manual says they will last 10 years and it hasnt, therefore its not fit for purpose.
what should i do guys cos i cant lock my car at the minute
20th Sep 2009 7:30 pm
lad
Member Since: 17 May 2008
Location: Blackburn
Posts: 634
I'm unsure about the charging part myself, I think I remembered that you may have to leave the key in for a while, like go on a good run, I think it doesnt charge it up straight away, but if I'm wrong someone will be along to put me right
Have a look at this link
Member Since: 17 Jun 2008
Location: widnes, cheshire
Posts: 117
thanx mate for the reply.
i see from the link that the batterys charge up using induction. according to the thread, the key doesnt actually have to be in the ignition for it to charge! it works as long as its near the stearing colum is this correct??
anyone else that can help me out please
20th Sep 2009 7:47 pm
lad
Member Since: 17 May 2008
Location: Blackburn
Posts: 634
You can lock the landy using the passenger door lock, have alook at this link
there is a cover over the passenger door lock, remove this and you should be able to lock it, be careful not to break the cover/key because it may be difficult to remove the cover as it might not have been off before
20th Sep 2009 7:55 pm
BBS SPY Site Sponsor
Member Since: 15 Jun 2007
Location: Sunny Cyprus
Posts: 3054
When a Key is inserted and the Ign turned on, a coil around the key slot barrel, is energized and emits a small electromagnetic field at a particular frequency. This is picked up by a coil in the key which converts it back to energy, albeit with some loss it is enough to charge the battery in the key over a long enough period, or more correctly maintain the charge to replace that lost when using the key to lock / unlock the doors.
If a key is unused for a long enough period, or usage is such that it gets depleted more than re charged it will go flat and stop working. I guess like any re chargeable battery, storing it totally flat for long periods can often prematurely kill them.
You note that the immobilization will still work as this is a totally separate circuit and functionality aspect to the door opening part, hence you can still start the car.
It seems that taping the spare key to the original while it is being used, does bring it close enough to also be charged at the same time.
So i suggest you tape them together and use them like that for a while, attempting to give them the best chance to charge (long journeys) and see if either comes back to life.
Other than that, or in the event both are truly duff, contact TLO for the best cost replacement.
If you do have a duff fob, then i guess you have nothing to loose by opening it up and having a look see if the battery can be replaced.
20th Sep 2009 8:16 pm
beesle
Member Since: 17 Jun 2008
Location: widnes, cheshire
Posts: 117
thanx for the advice mate.
i took your advice as i thought i had nothing to lose and opened up the key fob. I should really get some pic's up but im unsure how to post pics
anyway, the fob has a standard car key fob battery 3V but im assuming this battery is a rechargable type. The shaft (part that goes into the ignition is not connected by any means to the workings/electronics so im positive that the battery does not get charged via this. There is a little black box thingy on the circuit board which leaves me to think that this is what picks up the induction charge to charge the battery. There This explains why taping 2 keys togther helps to charge both up at the same tiime. it must have something to do with the circular metal ring that is around the ignition coil. ( the on that has 1 11 111 on it for the different ignition positions)
anyway, when i took mine apart, i took the circuit board out and long behold it started to work again. I can only think that it must not have been in the right position or ive knocked something but anyway its working now so im chuffed. so much for the stealers saying its knackered. anyway, im goin to look at my other fob tomorrow and try to get that working. so thanx guys for yer help. hope this helps out a few people here
20th Sep 2009 11:02 pm
Roel
Member Since: 16 Aug 2008
Location: home
Posts: 1215
I would love to see some pictures off the internals off the key fob. Uploading pictures is simple via the Gallery tab and then copying the link in the post.Roel
1997 Camel Trophy Disco ex-P101JWK (traded it for a Britains 42101)
1984 90 TD5
2005 G4 Disco 3 BN55WPT
Also member of club MTR
and Club Faultmate
Interested in my 4x4 history see my website: www.mudmachine.webklik.nl
Sorry it's in Dutch and with google translator it gets funny.
Member Since: 15 Jun 2007
Location: Sunny Cyprus
Posts: 3054
Well me being me, i could not leave it and so I took one apart earlier today and took some piccies.
But i see i inspired you beesle
It was supposed to be a spare one i picked up from a breakers for experimenting on some time ago but actually after i had took it apart i re read the label and i have actually took my own D3's spare one apart.
Fortunately i made quite a good job despite it being a of a job, I have done this before and it should go back together without too many scars from its open heart surgery.
Ain't superglue a wonderful thing.
So here are all the bits
Click image to enlarge
The black bit in the middle is rubber and forms a cusioned holder for the PC board.
You will also notice on the board the black oblong block at the top which is the chip antennea.
If you look in the location that would be under this bit, in the case bottom (to the left), you will see a pocket in the plastic that the rubber insert is shaped to go over.
I was most surprised to find that this did not contain the usual transponder chip for which it is most obviously designed, by virtue of its special shape. Cut off corner not visible in my photo due to angle of shot
Coincidentally, my wife has just requested my key, on the basis that hers is failing to work 100% of the time.
Colin, any tips on opening the fob? Is it much more than sawing through the glue?
I see that the batteries are easy to find online.Time flies like an arrow; fruit flies like a banana
Member Since: 15 Jun 2007
Location: Sunny Cyprus
Posts: 3054
Quote:
Colin, any tips on opening the fob?
Hmmn, i guessed i might be asked that
For sure no sawing or cutting was involved.
I started by picking on the least visible bits, namely behind the rotary key head and the bit where the printing is. There is quite a hole there when the blade is open and with something just the right width you can exert a lot of pressure to prise the two case halves apart.
You can't get at the glued bit as it is up or down, depending how you are holding it, inside a tongue and groove. so its really a case of putting constant pressure on wherever you are prising to exert enough force to get the glue join to rip / split apart. I put something in to wedge it open where i could while working the split point to make it run. As it starts to give one end, you have to be careful not to insert anything too deep as you risk damaging the board. I used a stout blade on a swiss army knife, a few flat bladed screw drivers of varying widths, a couple of wood chisels and a lot of swearing and grunting. I am also fairly confident that if i were not working on a rubber mat that i would have at least one hole in my hand. As such i disclaim all responsibility.
It is certainly not something to undertake without patience, and tooling up, however it will come, its really only a case of minimising the marking and damage to result in the least noticable effect when putting it back together after. Of course if its just going to be the spare, then you might not be so concerned as to maintaining the asthetics so much.
You can also clean up any dinks on the case edges afterwards to some degree too.
Hope this helps
21st Sep 2009 8:06 pm
beesle
Member Since: 17 Jun 2008
Location: widnes, cheshire
Posts: 117
well done BBS SPY
you saved me the hassel of opening the key back up to show the internals.
anyway, does anyone know which bit of this circuit board recies the indution current that therefore then charges the battery?? im intrigued
21st Sep 2009 10:05 pm
ad15
Member Since: 14 Dec 2008
Location: up that tree
Posts: 4866
i got told that if you tape a small "vibrator" to the key it will "charge" from the batteries in said vibrator.....one wife.......livid
21st Sep 2009 10:09 pm
Roel
Member Since: 16 Aug 2008
Location: home
Posts: 1215
Thanks Colin.
Nice to know how it looks like.Roel
1997 Camel Trophy Disco ex-P101JWK (traded it for a Britains 42101)
1984 90 TD5
2005 G4 Disco 3 BN55WPT
Also member of club MTR
and Club Faultmate
Interested in my 4x4 history see my website: www.mudmachine.webklik.nl
Sorry it's in Dutch and with google translator it gets funny.
22nd Sep 2009 7:34 am
Renton
Member Since: 13 Jan 2009
Location: Somewhere in the middle
Posts: 1718
I have replaced the batteries in 2 spare keys. However they still don't work. Can I leave the key in the ignition for a while or does the car need to be running?CLUB ILLEGAL CAR WASHERS
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of a job, I have done this before 
and it should go back together without too many scars from its open heart surgery.
