Hi again all. 2008 XF 4.2 SV8. There is one strange fault with the door locking system that is a minor inconvenience destroying my life. It is affecting only the left rear door. When I exit the vehicle with the key in my pocket and press the button on one of the door handles, all the doors lock correctly. When I approach the car with the keys in my pocket and grab the drivers door handle, all of the doors unlock except the left rear door. If I then want to get something out of the back seat by that door, I have to use the fob button to unlock it- and it unlocks just fine that way. If the car is locked and I grab the left-rear door handle (with the key on me), all of the doors unlock including that door.
I have unlocked the car by grabbing the drivers door handle whilst watching the inside of the left-rear door and there is some movement at the lock tab but it is not unlocking- like it is trying to unlock but not throwing far enough.
I am incredibly lazy love the feeling of pampered superiority convenience of the auto locking / unlocking / starting setup wherein I can just forget what pocket have the key somewhere on my person and do whatever I need to do without putting down my beer getting the key out. The rare odd occasion when I want need to get something out of the back by the l/h/r door is the only time this lets me down and I have to go fishing in my pockets for the key like the poor folk do. I'm sure you guys will understand how humiliating and upsetting it is to actually have to get the key out to unlock a door. What must people be thinking when they see me doing this. Sigh. Any help with getting this minor niggle sorted important part of my life back on track will be appreciated.

 

You need a new actuator in that door. I've had the same in my XF-R. They are a bit of a faff to fit as you have to take the glass out of the door but with a calm head and the right tools it can be done on the driveway in an hour or two.

 

Thanks for the reply Toxo. I'm puzzled that the actuator is responding differently to inputs from the 3 different sources, i.e.works fine when unlocked with the fob, works fine when unlocked from it's own door handle, fails when unlocked from another door. Does this gel with an actuator failure?

 

 

Thanks for the video link; I actually watched that video last night after finding it via a google search. A very handy detailed instruction on the actuator replacement.
My question remains though, is the varied action of the locking mechanism- dependent on the signal source- consistent with failure of the actuator? The vehicle in the video is not showing the same problem as I am getting.

I'd be interested to see what the actual failure in the internals of the actuator is in the above video- he shows the actuator internals but no detail on what has failed. I owned Range Rovers for many years and the door actuators were a frequent failure point and based on the same principle- a little electric motor driving a gear train that ends with a rack. On some actuators, the motor would burn out; on others, the pinion gear would strip. I used to dismantle the failed actuators and salvage the good gears out of the ones with a bad motor, and vise versa, combine the good parts and reassemble a working actuator. I wonder if the same could be done with these- although these days I'm not sure I could justify the time for the cost of a new part.
I note that these actuators have two motors in them (seen in the above video at about the 27:14 mark)- could it be that the failure is in one motor and not the other? I'm intrigued to pull one apart now.

 

The symptom of trying to unlock but not throwing far enough (so the lock part of the interior handle twitches) is 100% in line with actuator failure. I'm trying to remember exactly how mine behaved when it went but it was a while ago. It did seem at the time that it would lock through some mechanisms but not others. Almost the reverse of yours actually. The keyless entry actuators are different to the traditional keyed entry ones - knowing JLR the keyless functionality is probably bodged on over the top of a normal actuator leading to illogical behaviour!

Not sure where you're based but the cost of a new front actuator from the dealer was £151 inc vat in the UK last year. I had to do the same job in my E46 BMW at the same time and the equivalent part from BMW was £90, and they are known for having expensive parts! The fitting job was much easier on the BMW too...

 

Yes agreed the twitching lock tab does sound like a stripped tooth or similar in the actuator doesn't it. The partial failure has me puzzled but the two internal motors might be a clue. I'd love to pull it apart and come up with a permanent repair (I have a well-equipped home machine shop including gear cutting capability) but I wouldn't be game to disable the vehicle without a replacement on hand. Won't be springing for a chicom copy either.
Anyone have a busted actuator they would like to send me for investigation?

 

I discovered last night that, under some circumstances, the left rear door is not locking. This makes it more important to get the lock fixed. I priced the actuator from a Jaguar dealer nearest to me and it was a little over AU$500.00!!
Looking on eBay there are some sellers in UK and US offering what they claim to be genuine Jaguar part for around the AU$120 mark. Not having had the Jaguar very long, should I be wary of the possibility of poor quality fake parts?