Remote Key Fob

[Ippypicasso]

Hi, hope somebody can help.
I have a 2002 HDI Picasso, and my remote fob has stopped working. Changed the battery twice, using a Halfords Energizer, and still it refuses to work.
I've checked all doors are firmly shut, and the boot. I've even tried various suggestions for reprogramming fob to car by inserting in ignition, turning on ignition and pressing buttons but still nothing. The problem started about a week ago, fob opened car fine in the morning, but then when I arrived at work it stopped working. Waited until lunchtime, tested fob again and it worked fine ... until the following day when the same happened again, fob OK in morning, stopped working when I arrived at work, started working again later. Now it doesn't work at all.
Any ideas ? It's driving me nuts
Thanks
Pau

[Hell Razor5543]

It is known for the crystal in the fob to fail. I know it has something to do with the transmission frequency, but no more than that.

[citroenxm]

Sometime also, they loose "Communication".. Dont get mixed up the Trasponder Chip that allows you to start the car is completely indipendant to the Locking Fob.

Had this on a Xsara and a Mk.1 C5, but didn't get them talking again untill I put it on the Lexia...

I cant tell you why they stop talking though..

[ej2095]

You did lock the doors via autoloc button when trying to resync fob?

[Hell Razor5543]

I would be inclined to have a very close look at the board for any failing solder joins. A dry join has a grey colouring, while a good one is much more silvery. If I found any, and I was good with a soldering iron (I am not good enough for surface mounted components, especially ICs) I would try to re-do them.

[Ippypicasso]

Thanks, will check out the circuit board for bad soldering.
Also, ej2095, no I didn't press the auto lock button on the dash, should I have ?
Finally, is the process put key in ignition, turn ignition to on, press and hold lock button for five seconds, remove key, wait five seconds then try fob ? I've read different versions.
Thanks

[ej2095]

Had same issue on my C5

Thing would not sync was a right pain.

SO thought would lock doors via the lock button

Did the put key in tourn on ingniation with the lock button on the fob pressed counted to ten.

Both of the indicators of the car flashed and hey presto fully working fob