Focus boot opening at speed

Hi, Ford Focus 2006 hatchback.
I have the usual "Key Fob only sometimes unlocks the car" thing, which I
understand is probably bad connections in the driver's door lock.
I'm not really bovvered by this as I can always get in with the key, and
stop the resulting dashboard bleeping by turning on the ignition.
Maybe I'll fix this one day.
The boot always unlocks via fob, and I can always double lock the car with
fob.
(If the unlocking fails and I get in mechanically, the dashboard alarm
sounds, and the fob's unlock doesn't always kill the dashboard alarm, so it
may just be a fob switch prob)
But the other thing is that the boot will randomly unlock whilst I am
driving.
It's done this several times now, one time going through perhaps 8 instances
of the solenoid clicking away.
Today it did it on the M25, heading north at the north exit of the Dartford
Tunnel with a load of stuff inside and nowhere to stop - a bit scary
imagining all my stuff pouring onto a heavily congested carriageway.
So now I realise this isn't a trivial problem.
It seems the boot lock (hatchback) is a two stage device like the bonnet?
i.e. it can unlock to one level, but needs a second unlock to fully open?
I say this because when I eventually was able to stop on the hard shoulder,
I couldn't open the partially released boot, (keys still in ignition) but
could push it fully shut.
Cheers,
Gareth.
Reply to
Gareth Magennis
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[...]
Found this, which might help:
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As the faults you are having with the central locking are affecting different parts of the car, my best shot would be a failing central locking module. AIUI, these may be coded to the vehicle. :-(
Chris
Reply to
Chris Whelan
The boot switches can fail due to water ingress, usually they fail to work at all when this happens but rarely they can go intermittent.
Happened to my cousin's Fiesta which uses a similar design, changing the switch cured it - though she did not have the other faults you have reported with the central locking.
Reply to
Lee
On Tue, 18 Jul 2017 10:34:18 +0100, Lee wrote:
Try spraying contact cleaner on the components first , the faults often a water track on the circuit board and the cleaner will remove it
Reply to
steve robinson
On Tue, 18 Jul 2017 10:34:18 +0100, Lee wrote:
Try spraying contact cleaner on the components first , the faults often a water track on the circuit board and the cleaner will remove it
********************************************************
Thanks for the replies.
I'm struggling with the logic that water ingress/dirty switches can make a solenoid operate on the move.
I did read whilst Googling, however, that some people have had the boot come open whilst pressing the brakes (i.e. brake light circuit triggers it). Perhaps this is a similar symptom to the non model specific one where an earth fails on the rear lamp cluster, that causes the indicators to flash the brake lights and/or vice versa? Dunno, but I put my lights on in the Tunnel. Other times the solenoid has operated were during the day.
Cheers,
Gareth.
Reply to
Gareth Magennis
On Tue, 18 Jul 2017 10:34:18 +0100, Lee wrote:
Try spraying contact cleaner on the components first , the faults often a water track on the circuit board and the cleaner will remove it
********************************************************
Thanks for the replies.
I'm struggling with the logic that water ingress/dirty switches can make a solenoid operate on the move.
I did read whilst Googling, however, that some people have had the boot come open whilst pressing the brakes (i.e. brake light circuit triggers it). Perhaps this is a similar symptom to the non model specific one where an earth fails on the rear lamp cluster, that causes the indicators to flash the brake lights and/or vice versa? Dunno, but I put my lights on in the Tunnel. Other times the solenoid has operated were during the day.
Cheers,
Gareth.
***********************************************************
Found the fault, the external tailgate switch. Or rather it's wiring.
Wiggling the wire made the solenoid chunter like crazy, must be an internal short. New one on ebay, less than 6 quid.
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Not sure why Ford would not include the speed sensor in the tailgate release circuit, they do it with other stuff like the seatbelt alarm. The thought of jettisoning the boot's contents on the motorway into the path of a motorbike doesn't bear thinking about.
Cheers,
Gareth.
Reply to
Gareth Magennis
[...]
The door lock system has its own 'computer', so wouldn't have access to the speed signal in the engine computer's software. Vehicles generally run three networks now, and are segregated to minimise risk of something corrupting, say, ABS systems.
It would make sense for that interlock to be present however.
Chris
Reply to
Chris Whelan

[...]
The door lock system has its own 'computer', so wouldn't have access to the speed signal in the engine computer's software. Vehicles generally run three networks now, and are segregated to minimise risk of something corrupting, say, ABS systems.
It would make sense for that interlock to be present however.
Chris
Reply to
Gareth Magennis

[...]
The door lock system has its own 'computer', so wouldn't have access to the speed signal in the engine computer's software. Vehicles generally run three networks now, and are segregated to minimise risk of something corrupting, say, ABS systems.
It would make sense for that interlock to be present however.
Chris
Reply to
Gareth Magennis
Isn't there usually a gateway between the various CANs though? For instance to allow radios to do speed-sensitive volume and lock the doors as you drive away?
Reply to
Chris Bartram

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