Keyless Entry Fuse(s)

[quaffa]

Hello.

I have a late-2018 Fiesta Titanium 1.0 litre EcoBoost, and it has Keyless Entry as an option.

Recently I've noticed that the nearside door sensors do not work at all. Neither for unlocking or for locking. The offside (driver's side) door works fine.

I am aware that it is possible to disable the nearside, and I have checked in vehicle settings to ensure that is not selected; it is set to all doors. I have also recycled it through both settings.

I tried booking the car into a dealer, but they told me it has to be left all day 'because it is a diagnostic' and they tell me I cannot wait on the premises. I don't want to use public transport or a taxi to get home at the moment, and so I told them I would leave booking it in until the lockdown rules are eased a bit.

And then I thought that perhaps it is something as basic as a fuse, but I cannot find in the user manual a fuse for keyless entry. I've seen a video on YouTube about keyless entry on a Focus, which has two fuses for it, (one for each door?), but of course a video about the Focus isn't any help for a Fiesta.

Is there any possibility that someone on here might have the information about the fuses used for Fiesta keyless entry, and which box they might be in?

Thanks in advance.

[MarkRS9]

On my Focus when the battery level is a bit low it turns the passenger side keyless entry off, until the battery is charged back up.

I imagine it's the same on the Fiesta.

[Comares2001]

Almost certainly low battery ,your handbook will probably tell you somewhere that when battery charge is low some features will be disabled. Fuse idea you are looking for is last century stuff. Apart from one or two items things like locking,windows,lighting etc etc are all controlled by dedicated modules that are linked to main control modules via Canbus

[quaffa]

Thanks Mark, that sounds like what might be the problem. I haven't checked the charge in the battery, but lack of use owing to lockdown means that it isn't getting regularly charged. The Auto-Stop-Start isn't working either, and I'd realised that was probably the battery. It hadn't crossed my mind that it would affect the keyless entry as well.

Brian, you've made me feel very old!

Thanks to you both, anyways. I think a long run round and round the local area is the order of the day tomorrow...

[quaffa]

Well, I took the car out today for a couple of hours on the motorway, but it wasn't all that successful. The Auto-Stop-Start never resumed working, with the icon remaining greyed-out on the dash whenever it ought to have kicked-in. So I cannot say that the battery was fully charged by the run.

The nearside keyless entry is still not working either. The user manual says 'the system will not function if the vehicle battery has no charge'. So it doesn't specifically mention that only half of it will not function at any time, and nor does it say that an only partially charged battery will cause one side to stop working.

Of course it might be said that something on the dash to indicate the state of the battery would be a useful thing to have in vehicles that rely so much on the battery. The car always seems eager to repeatedly throw up virtually useless warnings about all manner of things, such as seat belts and the sat-nav, but nothing about the battery charge being low...

[Comares2001]

Get in your car make sure sync3 is on but don't start engine. If battery is low you will get a countdown warning on the sync3 telling you the system will shut down if you don't start the engine. It will likely need more than the run you gave it to get the battery up to the 80% required. Basically it's because much of time you are driving, dependent upon various conditions the intelligent charging system is not actually charging the battery. It does a balancing act of reducing emissions by reducing charging whilst making sure there is sufficient charge in the battery to start the engine.Thats why when the battery charge falls below the prescribed threshold various vehicle features turn off. Of course there's always the possibility that the battery itself is underperforming. Best thing is to give it a boost charge with a charger. Lots of us on here have had to do this during lockdown. Lots of posts on this subject on the forum.

[quaffa]

Thanks again Brian, I will try the Sync3 thing and see what happens. And invest in a battery charger, which I thought I'd seen the end of the need for ages ago.

14 minutes ago, Comares2001 said:

Basically it's because much of time you are driving, dependent upon various conditions the intelligent charging system is not actually charging the battery. It does a balancing act of reducing emissions by reducing charging whilst making sure there is sufficient charge in the battery to start the engine.

Is it just me, or does anyone else think that the more 'intelligent' machines become, the less we should have to think about them, and not more? It seems everything has to be second-guessed these days. My dad used to be able to fully charge the battery in his old A35 in a half-hour run back in the day.

(Still feeling old...)

[quaffa]

Brian & Mark, reporting back after investing in a battery charger. After a couple of hours on charge everything works again as it should, both keyless and the A.S.S.

Thanks for pointing me in the right direction.