Runs but wont lock/unlock

Dave1 · Post by **Dave1** » 17 Nov 2004, 23:06

I have a 306 with deadlocking, transponder but no alarm.
Something seems to have happened to the key (like it may be Kn***ered) in that it will not lock/unlock the doors. When pressing the lock button, the red light does not come on, but does flash once after it is released. The 2nd key works fine and the red indicator light comes on when pressing the button. This would seem to show there is a problem with the key sender. Peugeot charge a lot to provide a new key and match it to the transponder. A friend who fits alarms and makes control units for a living says Peugeot are the only ones who can sort this out on their bay as a new key needs matching to the car (with the 4 digit code etc).
Is there a way?
Oh, tried new batteries!
Dave

PowerLee · Post by **PowerLee** » 17 Nov 2004, 23:57

You could try a second hand key programmed to your car, Have a look on this forum on how to do it.
Just swop the small black transponder chip from your broken key to the new second hand key.
Do this on a white cloth on a table because the chip is really really small & easy to lose!

Dave1 · Post by **Dave1** » 18 Nov 2004, 01:44

Thanks PowerLee,
I think that is the way to go.
Dave

PowerLee · Post by **PowerLee** » 18 Nov 2004, 01:59

You can just swop the metal key blade & the transponder chip over to the new key, Be carefull with the chip, its small & black & easy to lose!
If you have or can borrow a small wattage soldering iron you can try reflowing the solder joints on the pcb to see if that helps fix the key, Seeing as its broken already you cant really lose anything by trying.

samcro · Post by **samcro** » 18 Nov 2004, 14:04

Dave,
Just to clarify..
Have you got two keys with 'zapper' central locking units in them? One works fine and the other not?
Im led to believe that the code such keys send out changes each time you press the button. ie it advances to a new code so it never sends out the same one twice. When the unit in the car receives a signal from the key and locks/unlocks, it also moves onto the new code. The car will accept the current code or a number of future codes (incase you press the button away from the car and advance one code and not the other). This code is NOT the 4 digit code from peugeot but is derived from that.

Peter D · Post by **Peter D** » 18 Nov 2004, 14:12

How about a new battery in the Fob. Regards Peter

Dave1 · Post by **Dave1** » 19 Nov 2004, 02:28

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by samcro

Dave,
Just to clarify..
Have you got two keys with 'zapper' central locking units in them? One works fine and the other not?
Im led to believe that the code such keys send out changes each time you press the button. ie it advances to a new code so it never sends out the same one twice. When the unit in the car receives a signal from the key and locks/unlocks, it also moves onto the new code. The car will accept the current code or a number of future codes (incase you press the button away from the car and advance one code and not the other). This code is NOT the 4 digit code from peugeot but is derived from that.
<hr height="1" noshade id="quote"></blockquote id="quote">
Hi samcro,
Yes two keys, one works. However, the faulty key's indicator/function light does not light up when pressing the button, which leads me to think it is faulty. It flashes after pressing it. The "good" key has a light which comes on when you press either of the butons.
Dave

Dave1 · Post by **Dave1** » 19 Nov 2004, 03:25

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Peter D

How about a new battery in the Fob. Regards Peter
<hr height="1" noshade id="quote"></blockquote id="quote">
Peter,
tried this as per the note on my post
Thanks

Peter D · Post by **Peter D** » 19 Nov 2004, 13:26

Sorry missed that.
Right I suspect the smal microswith is away with the fairies and need to me replace, Perhaps you mate can do that. I have replaced several of these on VW fobs. Get you mate to meter the switch I suspect that it is only powing on for a split second then again on releasing. Regards Peter

samcro · Post by **samcro** » 19 Nov 2004, 14:02

Dave,
Don't take my word for it, but it could be that the non-working key has got too far out of synch with the code in the car (see what I said previously about car and key fob advancing to a new code). Hence the light coming on after pressing the button. ie. maybe an indication that its attempt to lock/unlock the car was unsuccessful.
Unfortunately i've no ideas on how to verify this or rectify it.

TomH · Post by **TomH** » 19 Nov 2004, 17:24

er, so if you play about with the key in your pocket you could mess it all up? didn't know that one!!

solara · Post by **solara** » 19 Nov 2004, 18:04

I have actually traced the infra red signal from my keyfob using a storage oscilloscope and infra red sensor.
Guess what, the infra red signal is fixed, and does not change between button presses. Fairly easy to hack and make a "universal" key! That must be why peugeot introduced the transponder.

samcro · Post by **samcro** » 19 Nov 2004, 20:58

I guess that you could potentially upset the system by blipping the key fob lots of times. But this is usually LOTS of times, like 1000's.
Maybe Peugeot dont use this system, as implied by the previous post. That's a bit worrying if it's always the same code. Makes it pretty easy to hack!

PowerLee · Post by **PowerLee** » 19 Nov 2004, 22:51

The Peugeot infra red key uses the same code every time, It doesnt have a rolling code!
The transponder only works the imobiliser, It has no effect on the remote locking.

Dave1 · Post by **Dave1** » 20 Nov 2004, 04:20

With both keys in the house away from the car, one keys lights up correctly and the other flashes after pressing it. Neither would know if it had unlocked the car or not. Hence I feel the key is faulty rather than differing in signal to that which is required. I feel the easiest and mid priced method will be to just buy a new key, program it work the locking and swap the chip as PowerLee suggested. I have looked on ebay, the infra red ones are not in the majority and there are things stated like "it lights up but cannot confirm it works so sold as seen" (£30 too.) I can get a new one for not much more. I don't mind that too much, but I do not like the extra charges for the garage labour(leaning on the car,having a fag, displaying driving ability in the workshop), so chip swap seems best, unless of course, you know better!!
As it stands I am happy with the help given which will save a few pounds and keep the car away from the Pug dealer.