Key fob jot working

[boristhespie]

I left my 136bhp 2006 C5 hdi sitting for 3-4 weeks. Started it up occassionally but left it for two weeks at end without. Anyway key fob remote locking disnae wirk now.

I changed the battery but still not working. There was a lot or grease inside. I gave it clean. Still not working. Bit weird because was fine. Not done diddly to it.

Any ideas?

[GiveMeABreak]

Yes, batttery!

After 2 weeks with only a tickover or two it won't be enough to keep the car battery in condition. The charge will also slowly dissipate over that time and that can affect the ECUs. A lot of systems stay active on the car - for example the aerial receiver awaiting an unlocking signal - all that takes power. You'll need to take the battery off and give it a good overnight trickle charge. Then follow my procedure for reconnection exactly:

Battery Disconnect / Reconnect Procedure

That should reinitialise the ECUs, but it is important that you follow the timings to allow them to restart properly before trying to start the car or it will just do the same.

If you have changed the fob battery the part where you put the key in the ignition will also resynchronise the fob.

[boristhespie]

Sorry, I should have made it clear that I changed the fob battery. Not the car battery.

[GiveMeABreak]

Yes, I understand that! I'm talking about both - charging the car battery and also resynchronising the fob battery as you have changed that. I've edited my post to refer to car battery in the first sentence. The car battery will discharge considerably over 2 weeks is what I am saying.

If you have TPMS - that also actively reads data from each of the sensors on the wheels periodically even when the car is not in use, then there is the alarm, the volumetric sensors added to the central locking receiver awaiting a wake up signal from the remote.... So you can see how the battery can quickly become discharged. Putting the shunt into Park configuration and disabling the volumetric sensors before you lock the car will turn off some of the power consuming equipment if it is going to be left for some time. Just ensure you replace the shunt fuse back when you are ready to start using it regularly again.

[boristhespie]

Ok. I will give this a go. I have driven the car however. I'll let you know how I get on.

[Hell Razor5543]

You might be able to get a solar panel from Aldi (for £25) if you ask nicely. They had them for sale a month or so back. When I called into my local Aldi last Tuesday they were no longer on display, but when I asked about them a store assistant went out back and got one for me (which I gave to my brother). They are not high powered (just designed to provide a maintenance charge; 12V at 6W), but they should keep the battery topped up. They can connect either via a cigarette lighter socket (provided the socket remains live with the key removed) or crocodile clips that can connect to the battery.