Keyless lock/unlock only working on drivers door

[unofix]

My Focus MK4 has Keyless lock/unlock on all 4 doors, or at least it had a few weeks ago. Today I tried to open the front passenger door - but it refused to unlock, so then I tried each of the rear doors and the same, it would not unlock, (using the buttons on the keyfob works on all 4 doors)

The drivers door keyless lock/unlock is working fine. So my first thought was that some how the lock/unlock drivers door only has been accidentally selected but no. I've tried selecting and deselecting 'Drivers door only' and 'All doors' but still keyless entry remains unavailable for the 3 passenger doors.

Any help on this would be much appreciated.

[alexp999]

Low battery?

[unofix]

I did wonder, but I'd had just parked up after a 12 mile drive. I'll stick a multimeter on and check.

[Tizer]

If you connect up FORScan there is a PID for battery State of Charge in the BCM.

[unofix]

Checked battery with a meter, only 12.02V which given I've just done 2 x 12mile journeys I would have expected better.

Have put the battery on charge and will leave overnight and hope the locking sorts itself out in the morning.

[Tizer]

14 minutes ago, unofix said:

Checked battery with a meter, only 12.02V which given I've just done 2 x 12mile journeys I would have expected better.

Have put the battery on charge and will leave overnight and hope the locking sorts itself out in the morning.

That is a bit low. I know from my own monitoring that just waking up the car causes a large current draw and a one hour run might only add 3 or 4 % to the SOC depending on whether it is charging conventionally or one of the other modes. 

[Wino]

At 12.02v it should be working. 

My voltage is rarely above 12v and I use the  front and rear passenger door lock most days.

I know it will work as low as 11.2v but I must add I dont use a multimeter just the plug in gizmo.

[MasterTechTip]

If battery state of charge is below 40% all keyless functions of the vehicle stop working as a power saving mode apart from the driver's door, this was a new "feature" when the new fiesta came out and has since been used on all new vehicles after it👍

[unofix]

Just to update this, after a full 24 hours on charge the battery standing voltage has gone from 12.02V to a healthy 13.96V (I expect that will fall back a little in the next few hours).

Had to do a full ignition cycle, and start engine then as if by the magic of Harry Potter's wand .... All the keyless lock / unlocking are working again 👍

[Eric Bloodaxe]

49 minutes ago, unofix said:

Just to update this, after a full 24 hours on charge the battery standing voltage has gone from 12.02V to a healthy 13.96V (I expect that will fall back a little in the next few hours).

Must admit, until recently I'd never really appreciated what (in voltage terms) 40% charge really is. 

Learned a lot last year during lockdown through various threads on here about battery condition, "smart" charging, etc.

[Tizer]

1 hour ago, Eric Bloodaxe said:

Must admit, until recently I'd never really appreciated what (in voltage terms) 40% charge really is. 

Learned a lot last year during lockdown through various threads on here about battery condition, "smart" charging, etc.

The problem with these cars is that they have a massive current draw when you wake them up and just sitting with the Ignition on can draw anything from 8 to nearly 20 Amps depending on whether the Auto lights and Heating fan etc are on so to get a meaningful reading you need to open the Bonnet and measure at the battery after leaving the car for 1/2 an hour or so until everything is shut down.

If you plug something into the cigarette lighter then you will always get a falsely low reading.

[MasterTechTip]

Yup new cars are crap as little run arounds now, guarantee if you only do a mile or 2 a day expect a flat battery in a week

[Wino]

3 hours ago, Eric Bloodaxe said:

Must admit, until recently I'd never really appreciated what (in voltage terms) 40% charge really is. 

Learned a lot last year during lockdown through various threads on here about battery condition, "smart" charging, etc.

Intresting chart. Thanks for posting it. 

Looking at those numbers our Focus sits comfortably at 30%-40% it's very rare for it to show 12v after being left o overnight or a few days.

Something tells me that the little gizmo must be telling me porkies because if I park up after my work  shifts are done (Sunday night) and dont use the car for until I go back (Wed/ Thurs) then it generally reads 11.5/11.6v 🤔

[Eric Bloodaxe]

14 hours ago, Wino said:

Looking at those numbers our Focus sits comfortably at 30%-40% it's very rare for it to show 12v after being left o overnight or a few days.

Yes, I found the same, though it's never failed to fire up first touch of the button so far. Getting a bit more use now of course, as the worst of the restrictions are (hopefully) behind us!

 

16 hours ago, Tizer said:

If you plug something into the cigarette lighter then you will always get a falsely low reading.

Found that too. So I also use the meter on the battery to get a reading.

 

Done more battery checking/charging in the last 18 months or so than in the previous 50 years of driving!😀

[StephenFord]

13 hours ago, MasterTechTip said:

Yup new cars are crap as little run arounds now, guarantee if you only do a mile or 2 a day expect a flat battery in a week

Can't help agreeing with you. My mum, in her 80s, has a 20 (!) year old Toyota Yaris, used it for about 10miles/week, and it never failed to start once, even when unused for 3 consecutive months in lockdown! I love driving it as it has a sunroof, and icy cold A/C which hasn't been touched since new - you can tell it's not a Ford LOL

[Eric Bloodaxe]

2 hours ago, StephenFord said:

My mum, in her 80s, has a 20 (!) year old Toyota Yaris, used it for about 10miles/week, and it never failed to start once, even when unused for 3 consecutive months in lockdown! 

Presumably it lacks the "benefit" of "smart" charging!😀