The seat doesn't actually need to come out, I removed mine as I had no clue how to get the back off & the info I'd got from forums / peeps who'd done it themselves seemed to be inconsistent.

(Hopefully this will help - read this as as if it were the drivers seat - but I am going from memory)...

The seat-back leather trim that is tucked & clipped under the seat is unclipped (I re-hooked it to the seat back pocket for convenience so it didn't get in the way). Dead easy - 3 second thing.

There's a white piece of plastic panelling on the rear lower part of the seat back -spanning across the seat, which is unclipped by pressing a tap which is on the inner side of that panel - same for both side of this panel. This is deceptively easy to get off - but don't pull it - until you've found the tab with your fingers. Then it'll come away from the side really easy.

Once that trims is removed (I disconnected the 12v battery & waited 10 mins owing to air-bags), you may want to disconnect the seat connectors from underneath (again, just thinking about airbags? Up to you).

I'd removed my seat-buttons trim entirely - but I don't think that's required - just the rear-ward part of that trim, nearest the seat back will need to be popped off, to allow the rear lower part of the seat-back cover to unhook - you'll probably see what I mean when your eyes are on it.

The lower rear right corner of the seat, where the seat-back cover curls around the back of the seat essentially unhooks - outward toward the drivers door / you. There's a plastic trim around a spindle which can be removed / popped out which might make it easier - but you don't need to do that IMO.

On the other side, rear back left corner, again - the seat-back unhooks off a spindle - trim needs to be eased aside to allow the seat-back trim to unhook off outward this time in the direction of the passenger seat / centre console.

Then the seat back cover, should, simply (with both lower corners that were hooked over the bottom of that seat spindle I referred to - unhooked) push down and come off in your hand. You don't need a lot of pressure - remember, this is supposed to be somewhat easy - as the seat filters are a service-swappable item - so LR don't remove the seat to get at them!

The seat-back hooks onto these hooks / large downward facing pins (yellow circles) - so the back (on my 2011 4.4tdv8) definitely moves down:

Click image to enlarge

Great write up. Ive just removed my seat back using this very method.

I have the symptoms as described previously i.e Cold Setting - Fan runs constantly. Hot Setting - Fan runs for about 10 seconds the cut out, all control lights stay on.

Reading this thread it looks like I need a replacement seat back unit. I have an IID on order. I’ll wait for that to arrive to confirm the fault before diving deep into my pocket.

Take the seat back off then & see if the ducting is cracked or in anyway compromised - if it is, that’s your problem & you’ll need the seat motor regardless.

If you look at the corrugated black ducting right in the middle of the seat-back, on the last pic I posted - can you see the big hole in it? That’s the issue - Air needs to be directed uniformly over the sensor in the peltier cell or the ECU will disable the seat as soon as it’s switched on again to inhibit overheat & ultimately fire I guess.

Tj2k
I have the seat back off and the ducting looks in good condition. So I’m guessing that the fault is with the temp sensor on the pettier cell as mentioned earlier.

At first glance, that does look ok - on the surface - from what I can see (heavily caveated! ).

I would next check the filter (this is really easy - you've done the hard part - if you get worried, take pics before & after you remove each thing);

..... remove the fabric clips (as described above) and then unclip that additional ducting (the two friction-screw things (what the hell are those things called!? ); behind that is the filter (big white fluffy circle - same as the one under the base that you can see if you pop your head under the front of the seat base).

So, attached to the base of the cell (hidden from view in that pic obv.) you'll find the filter - just check its clean, unobstructed & not interfering with the fan. The fan is behind the filter. Check that nothing seat wise is unduly pressing into the filter - or if the fabric had been wrongly fitted by someone before you (like a numpty dealer in a rush for his lunch-break!) - if fitted wrongly, the filter can obstruct the filter (if fitted wrongly) slowing the air velocity & causing the overheat warning.

It that looks ok, it could be that there are cracks in the corrugated ducting but they're either very slim or (more likely) hidden on the reverse side of those corrugations. In that case, as the fabric is now removed, pop the seat motor / cell out with those two clips (see my pics with circles) & check the reverse ducting (also check for clumps of dust etc too - of you find loads & no cracks, get an air can or similar and give it a er, blow-j*b).

My money is on obstructed airflow for whatever reason over the sensor in the cell - probably by compromised ducting.

The other thing you can do to definitively prove it - assuming your passenger seat works normally, is swap that one out (without removing the whole seat) & put it in situ on drivers seat & test it. You'll need to clear the codes obv (so your IID) to get drivers side working - unless you put drivers one in passenger seat & see if that side then breaks. Bit of a faff about though this idea.

From what I've read, the actual cells are very reliable indeed - it's usually air-flow related issues (ducting most often) that is root cause.

My ducting was cracked underneath, not immediately visible, I did a bodge with gaffer tape and it didn't work - but maybe I actually bodged the job. So I will remove the whole thing and see whats what and Dan has given me a price for a replacement if I need it. I find working with the seat out to be easier and as soon as I can ident a helper thats what I'll be doing. Last time I took a seat out by myself I found it to be heavy and awkward - a bit like myself really  Geoff

Supershuttle - what did Dan quote you for a price? Is it cheaper than £209 +vat?

tj2k
This morning I followed your instructions (Thank You) and removed the whole unit for inspection. I can see no cracks in the corrugated ducting, I even flexed it a little to see if there were any fine cracks.

I removed the filter and inspected it, its pretty clean, and inspected the ductwork for debris, its all clear.

I then ran the unit out of the seat with no air filter; it runs fine on cold, but as soon as I switch it to heat it runs for about 10 seconds. So it looks from the reading below, like a new unit is my option

Many thanks for all your help.

Zeppfish wrote:

Tinribs

JLR in their wisdom put a thermistor on the hot side of the unit, to stop a burned arse / seat, but no temperature control on the cold side. Sooo if its running cold but not hot, its the thermistor that is failing. If it does not run either hot or cold then it is probably something else with the fan unit being the first thing to check!

The other thing to note is that each seat has 2 units, one for the back, and one for the base! there is only a thermistor in the back unit, as this is the unit that runs all the time the heating / cooling is on!

Firstly run the seat cold, and see if it works indefinitely! if it does switch it over to hot. If it runs for a few seconds, and then the fan cuts out it is the thermistor i"m afraid and thats a new unit (the thermistor is bonded to the heating surface of the peltier cell)

£195+ VAT Geoff

Geoff (Supershuttle)
Many Thanks

John

I did have a thought - dangerous I know - but can the thermistor itself be swapped out as they are simply temperature sensitive resistors. Or is it as I suspect (because no ones wrote it up) not easily be done ? Geoff

I did think that as well, but looking at the cell, I can’t actually work out which is the "power" and whuch would be the thermistor. I think you may very well destroy the cell trying to change it

I’ve ordred a replacement part. When that’s fitted I’ll tear the old one open and see if we can find answers.

i will be looking forward to your update on the thermistor cell FF TDV8 WESTMINSTER EXTERIOR DESIGN PACK 2012

Supershuttle
The thermistor is sandwiched in theemiddle of the pelter cell . I had my old one apart it's a non serviceable part i'm afraid  2006 RR sport HSE
Swapped for 2012 4.4td v8 Westminster Santori black with Ivory leather
BEEN SMILING EVER SINCE