Repairing a Renault Laguna Card KeyA common fault with these keys is that one of the buttons stops working. You can tell when this is a fault with the key rather than the car because the led stops flashing. If both buttons have failed then first try the obvious and test the battery and make sure the contacts are clean. If so then you need to resort to one of two drastic solutions; buy another one (about £130) or repair it.
This is the type of key we are talking about, it is the type with two buttons and the safety slot in the end, not the proximity type. There may be other models that use a similar key, I have seen one with three buttons for instance, but I don’t know if they have the same weakness. The fault with these keys is that they use surface mount micro-switches and the “lock” one seems to be on a vulnerable part of the board which perhaps flexes and it drops off. Often you can hear it rattling loose inside.
The tools you will need are a good strong Stanley knife, a soldering iron with a very small tip (1mm or less), some long or curved-nose pliers, a strong magnifier and some super-glue.
The first task is to get inside. These are not clip-together cases, they are glued all round and on some internal ribs as well. On the photograph of my one below (click for a larger image without my annotations), I have marked the glue lines in red. The blue dots are unglued guide posts. With a strong Stanley knife and starting at the point marked “A” you can carefully cut along the edge, try to cut if you can as it doesn’t split very well—and watch your hands as the blade is liable to slip. When you reach the first bend “B” go back and do the first internal rib, then you can move round peering in the crack to see what to cut next. Be careful not to damage the components or the circuit board. A close inspection of the pictures shows the things to avoid, it is really a matter of patience, care and brute force.
As you can see, mine opened upside down, so the next step is to cut under the battery clip to separate the circuit from the case; I used a small kitchen knife to get in there.
So you should now have all the parts laid out including a loose button switch. This switch has a contact on each corner, two fold-under lugs to hold it together and two other lugs to help it stick to the board (ha! ha!). Sorry, the resolution of our camera is not good enough to see this detail. Near the centre of the circuit board you have a corresponding space with two pads on the earth plane at the top (arrowed blue), two on a track leading to the IC at the bottom (arrowed black) and two isolated holding pads (arrowed red). The orientation of the switch is important, the wrap around lugs MUST be to the sides.
With your fine tip soldering iron, clear up and tin all the contacts on the switch. Similarly clean the circuit board pads. You are well away from any delicate components here so there is not a lot of risk. Make a small solder bead on each pad. When I say small I mean small; I used a jewellers eyepiece to see what I was doing, scary with a hot soldering iron inches from my face.
Now lay the switch on top and test that it works by holding the battery in, and pressing the button. If you get the switch the wrong way around, the light will be on without pressing the button. Satisfied that it works you can solder the switch into place—holding the switch down with long pliers, touch the soldering iron to each corner and the top/bottom edges to get the solder to bridge the gap in six places. You may need to go round more than once as the component beds down to the surface. Test it again. As a final touch, I dribbled a bit of super-glue under the switch as an attempt to hold it more securely.
Now clean up the plastic parts with a knife, removing all loose bits and get the halves to mate together tightly without the circuit. You will also need to clean up the plastic part of the battery clip. Lay the circuit into the back cover, there should be two positioning pegs to hold it in place. Apply a drop of glue to the battery clip to secure it and leave it for a few moments to set. Finally run a bead of glue around the outside edges and the main internal rib, bring the parts together and clamp (clothes pegs) or weight it until it sets. How many of the original lines you do depends on if you are likely to want to undo it again but I would suggest omitting the front of the battery clip.
For the technical, the numbers on the components are: the big round piece (transmitter coil?) is 50751, the DIL package (encoder?) is Phillips PCF7947AT with other numbers 16793102 and DnD00350. The small silvery unit (oscillator crystal?) has EPC05, R727 and M5MN. A Google search didn’t turn up much.
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I think the batteries vary. My newest one has it in a little carrier and is a SONY CR1620 but the older key has a bigger battery without a carrier.
I just opened up mine and found that one side if the copper battery clips had snapped, bit of solder later and its sorted! cheers for the pics
Hi there guys . I have two falty keys but being a girlie and not knowing how to use a solering iron etc I dont think I can fix them myself . Would anyone attempt to fix them for say £25 as I cant afford to get a new key again – thanks ?
Hi Guys,
I have a mojor problem with my Languna II. The open and close buttons work fine so did the start untill last night!!!. i now insert the card and the car wont start.. the lights surrounding the card flash and the red immobiliser light on the dash flashes?!?! please please please any help appreciated as im already £150 down on recovery costs! Thanks
HI FRIENDs sorry.. I have megane2 2005.. I lose those card. and very expensive in turkey 200 euro. have I found a little cheap..or can I cange another key card’s pcf7947at chips, may car start??? please help.. is this card encode chip ???
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sometimes it’s just a battery issue, or just old wiring.
Thank you, stabbed my thumb with the sharp knife but certainly worth the few drops of blood! Before anyone says anything, yes I am a female! Seriously though, great help – Reanault have extracted enough dosh from me this year.
my laguna keycard had broken first it wouldnt lock then 3 months down the line it wouldnt open unless i used 2 hands and squashed and bent the keycard. needless to say i bent it a little too much and it cracked. the the other morning i stuck the card in the ignition and nothing happened apart from the radio coming on and the red light flashing on the dashboard. i troed to take the keycard to bits like it shows in the photo’s. this didnt happen as well as expected ( maybe because it was already cracked) but i am now left waiting for my new key to arrive at a cost of £130 from the local renault dealer.
Hi, have a Renault Megane car, trip computer says replace car batteries, did this but message never went away it stayed on the trip computer. Had car serviced and asked them to check my key card, staff said my card was faulty even though it works perfectly well apart from message on trip computer asking me to change battery? Also staff said my spear card would go the same way as I have never used it, I was keeping it safe for emergency use, staff said eventually both cards will de-program. Is this information correct?
Many thanks.
Noel Ivers
Hi Peter. I suggest you get a second opinion as I have never heard of this before. Though I do know that the Megane key is different to our Laguna ones. Ask on the Renault Forum Site – there are a lot of experts there.
Hello guys, my key is just locks/unlocks the doors not starting the car, is there any places to fix this in London?
Please if you know could you email me thanxs…
Email: aycanyumusak[at]gmail.com
Aycan
just to say i tried to repair my brothers laguna key and failed ,off went the car to renault to have his spare key coded only according to the dealer it is not possible,now he has to wait ten daysfor a new key to come from renualt, rip off or what,the main lesson that comes out of this is DONT BE A MUG, DONT BUY A RENAULT!!!!!!
Tony, I don’t understand why the spare key should need coding – it should already work (unless it came from somewhere else). You get two working keys when it is new.
Also, don’t think it is only Renault doing this. They all have this scam which they justify by “security” and it is a reaction to complaints that you could open and start their cars with a coat-hanger and screwdriver.
Hi all both my keys have failed on laguna 2001,one will work the ignition but nothing else,the second will just lock the doors,is there anyone in west yorks that repairs them? thsnks.
Dear All,
I have just droppes off my car at authorised mechanic, and after requesting a new key, they have stuffed the old one…and now I have to pay for a new “card reader”, costing about AUD$700!!!! All this as I just wanted a replacement as the locking mechanism is now failing on existing key…bloody french!!
Hi again…..so now the authorised renault dealership mechanic – in Cairns, QLD, has returned to me, my original key – mangled and butchered…some excuse about some corrosion, and the case was hard to get into …RUBBISH!! so again, I do not have a spare key…am going to lodge big complaint with renault – see how that goes…
Just had to get a new key for my 54 plate laguna. Cost me £140.12 inc VAT. When u go to get them replaced make sure u ask for discount as i did and managed to get the price down fom £159. When u think about it you deffo need a spare key as they take over a week to be delivered. Imagine parking ur car in a car park and losing ur key or drop it on the floor an break the keys. U r screwed then. Pain it the backside but at least it gives u piece of mind.
Yes, 3 years bought my laguna from 2001 (yes secondhand), did not take long until both keys started to malfunction.
Comment of Renault: when the key is not handled with care, then they can give problems..Does that mean that anyone who has problems with his keycard has probably abused his/her card?
Easy excuse for renault to walk away from his responsibiliy to deliver quality?
Had to order new card (ordered only one, because of the high costs)
…always handled my card with respect, but in everydayuse it can and will happen that the card falls to the ground..Good chanche than that the damage is done..
So Renault should develop a card that should be able to take the stress of everydayuse and not place the responsibility of bad design at the customer..anyway, that’s my opinion.
Think again when you want to buy renault..
At reanult garage in Milton Keynes today, lost my key, the only one I had, ordered a new one on the 16th September, arrived on the 9th Oct! It was meant to take 10 days max, 4 and half weeks later!! (Double buggie for my 3 & 1 year old in boot!)
Then to make matters worse! I get booked in to reprogamme the key, waiting, waiting, waiting, when finally they come out to tell me they can’t reprogramme my key because my Card Reader in my car is faulty!!! A new one will cost me £230.41!!!! Then I have to pay the reprogramming ontop of that!! The credit crunch is having a greedy effect!
Just followed your steps and repaired the spare key!
Micro switch had fallen off as you said, and the splitting the card was the most awkward part. The soldering step was easy because there were no other components near that part of the circuit. Thanks!