AndyRoo wrote:

Hi,

If I remember correctly if you keep it on cool then both back and base fans run by default, if you select back only then the base fan doesn't run. So on cool both should work fine even if you have a peltier fault.

However, it seems to be that if there is a fault with the backrest peltier then it shuts the back & base off after a few seconds if you've selected heat.

So if both your fans are running on cool, but just shutting down on heat then it's unlikely to be the fans themselves, they're just doing what they're told to by the ECU.

To be honest I've never known a fan go in itself, they're not stressed and the ECU will control them based on the backrest. It seems to me that they only have fault monitoring on the backrest. I've had the base peltier fail and it had no effect on the backrest nor the running of the base fan it just blew cold air.

If your passenger seat backrest heating is working, substitute that across to the driver's side, see if that fixes all the issues, they're interchangeable. If that's not working either then I'm afraid your going to have to take a punt on the faulty part, the backrest peltier being the most likelt source of the problem.

Sorry can't give you a definitive answer, it's not the most robust of systems and parts are hard to come by, hence why I opted to pull it and give it to someone else to fix.

Andy

Tinman wrote:

You looking for these?

Click image to enlarge

Click image to enlarge

So I ordered a GAP IID yesterday and it arrived today. Not had a chance to swap the passenger side fan unit to the driver side but having read the fault codes I think it might be a fruitless task anyway.

The codes relating to the seat seem be this stored in the driver seat module “ U3001-46 (2F) Control module improper shutdown - System internal failure - calibration/parameter memory failure” and this stored in the HVAC “ B1418-87 (2F) Front right - Seat climate control module - Bus signal/message failure - missing a message”. So as far as I can make out, it seems it could be a faulty seat climate module. That would make sense since neither fan unit works for cooling or heating.

I’ve posted a photo of the fault codes I found with IID and I’m going to have a dig around under the seat tomorrow to check wires and connectors just incase.

Do the seat controls light up on the centre console?

If they do, I'd turn a seat onto setting 3 of cooling, open the door and physically look at the fan unit under the seat, to confirm it is spinning or not. Do the same with the seat back. The seat ECU will trip the circuits to the seat on detection of a fault and therefore give the appearance of not working, when in fact they are operational, just only for a few seconds.

Next task would be to remove the seat back, unplug the peltier unit multiplug and put a multimeter across the blue and yellow cable. A healthy unit is around 10 ohms. A faulty unit often reads around 1kohm. 2015 Range Rover Autobiography 4.4 SDV8

I can confirm this tip of testing the Peltier by Gary is a must. I ripped mine to find LR had improved the corrugate ducting so it now doesn't crack on later models but the Peltier still fails. I have now located some replacements and I'm putting in an order. I'm glad I haggled 4k off the price of my L322 last month  Current yokes
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Sorry guys I’ve maybe not been as descriptive as I should have been. I tested the fan units the other day and both were about 15-20 ohms across the blue and yellow. Also had the filters off and watched the fans. The passengers side would kick in on cooling and the driver side would not even kick in for a split second, it’s totally dead. So it seemed as if the driver side was not working at all. That’s why I’ve focused in on the fault code about in the module instead of the fan unit.

I’ve had both backs off again this morning to recheck the fan units. The passenger side definitely kicks in on cooling and stays on. Driver side is still totally dead. I swapped the fan units around. The one that works (passenger side) is totally dead when in the driver side. The driver side works while in the passenger side. So I’m still leaning towards the control module. I’m away to check wiring now and see, fingers crossed it’s just a wire nicked somewhere.

Well I’ve always been a fan of checking the simple stuff first, maybe should have done it sooner but not really had the weather since I got the car. So had a break in the weather today so unbolted the seat and had a look underneath. For some reason it seems someone has been there before and unplugged the heated seat control module. After plugging it in I cleaned all the fault codes but I’m still getting the fault code “U3001-46 (2F) Control module improper shutdown - System internal failure - calibration/parameter memory failure“ so maybe they had been in fault finding and forgot to plug it back in. Anyway, I’ve got heated and cooled driver seat.

Hi,

Kinda weird that it would be unplugged, may be the previous owner had it off for some reason and didn't refit it correctly.

Good to hear it's working now, chicken dinner.

Andy Fuji White / Jet 2012 4.4 TDV8 Westminster

I’m all for an easy fix Andy. That’s two I’ve had so far, not sure how much longer my luck will hold out though!

Does anyone know suppliers of the Peltier units?

I purchased a repair on ebay before Christmas but the seller hasn't been in touch.

I am happy to replace the unit myself if I can get a Peltier unit at a decent price. 2012 TDV8 Autobiography Baltic Blue
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Hi All, firstly thank you for such a fab forum, most informative.

Can anyone share a link on how to take the seat base (not the back) apart to replace the complete fan heater cooler unit?
I had my Westminster plugged in and was advised to replace the whole unit which I am happy to do whilst it's apart.

Thanks in advance.

Dom

colalowe wrote:

... if I can get a Peltier unit at a decent price.

I am going down the adventurous route with this and I have a previously enjoyed unit from an X351 Jag on it's way so I can cabbage the peltier unit. Oddly this appears to be the identical part no. to the L405 RR so far as I can tell without actually having th eLR parts catalogue.
Only £40 so not a total disaster if it isn't a complete success. I believe the Peltier cells with integral thermistor are all the same.
Can't be too hard to depin a couple of connectors then repin.
I wonder if the connectors are the same? If so I might just plug it in and test before getting the machete out and leaping into the jungle. 2011c Vogue SE 4.4 Oil Burner
1991 Hilux 2.4d MkIII. Sadly goone due to space and time.
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2000 TVR Tuscan 4.0
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Quote:

Can anyone share a link on how to take the seat base (not the back) apart to replace the complete fan heater cooler unit?

Fla wrote:

I can confirm this tip of testing the Peltier by Gary is a must. I ripped mine to find LR had improved the corrugate ducting so it now doesn't crack on later models but the Peltier still fails. I have now located some replacements and I'm putting in an order. I'm glad I haggled 4k off the price of my L322 last month

This link is one of a few on aliexpress now. It is not the cheapest but the cheaper ones don't look as good particularly in the area of the airflow splitter on the outlet side. On the genuine ones the board protrudes from the heat sinks.

https://www.aliexpress.com/item/1005005487...ry_from%3A 2011c Vogue SE 4.4 Oil Burner
1991 Hilux 2.4d MkIII. Sadly goone due to space and time.
2008 Skoda Octavia Scout
2000 TVR Tuscan 4.0
Loads of crap. Gone