Malfunctioning heated & cooled seats

[Danws4]

Hi all,

I know this is a subject that has been written of previously, but having done much research and thread following I'm at an information crossroads as to what to do next.

My 2018 3.0V6 has heated & cooled seats, but the driver seat heating function in the backrest has failed completely, and I get intermittent working of the seat base heating function.

When I request seat heating, sometimes the fan will engage and I get the seat base warming (never get back rest warming now), but other times request will yield no fan and no heating at all - but this seems completely random, and can change in the course of a drive, so it clearly isn't reliant on an ignition reset or similar.

I have scanned the car with Topdon and get the following code error.

HVAC (HVAC Control Module)
B1426-13
Front Right - Climate Seat - Thermal Electric Device 1 - Open Circuit
Confirmed

When I have the scan tool attached, and clear the DTC's, with driver seat heating requested, the fan will kick in for a few seconds and then stop, so I think everything is working correctly with the exception of the seat backrest heating function, and as the error code suggests open circuit, I guess there’s a bone-fide failure there.

I have picked up from other threads that the heated / cooled seats use a Peltier Cell system to provide the heating and cooling via a ducted fan unit, which I guess must be installed within the seat back.

Can anyone confirm if my presumptions are correct, and that the correct remedy is to replace the Peltier Cell unit in the seat back?
Also, as this is my daily drive, and I don’t have many hours left in the day for stripping down the driver seat just to find a product code, would anybody know the correct part / product code ref that I would need to be ordering for a new Peltier Unit?

 

[scm]

Your presumption about the Peltier cells is correct, but whether it's the cell or associated wiring at fault is something that should be investigated.

Good luck!

 

[Kev]

It would be worth pulling off the wiring harness connectors and re-seating them just in case there's a loose connection. Check for any broken wires or if there are any obstructions in the fan ducting before going down the road of replacing the Peltier

 

[RPSN]

I’ve attached some TOPIx information which should assist you.

If you need the Interactive Electrical Wiring Diagrams (iEWD) contact Member Philskill as he is very good with these. Here’s an example...https://www.ftypeforums.co.uk/viewtopic.php?p=53675#p53675

This is a link for the seat heater parts diagram...
https://parts.jaguarlandroverclassic.com/parts/index/part/id/152.1073.2421.11331/brand/jaguar/

Have a read through this...

 

[Jimmyrn85]

Let me know how you get on, I had a faulty seat that wouldn't cool, it cost me £1000 which was parts and labour at Jaguar Saltash to fix (replace components in seat).

 

[Danws4]

Thanks all for your comments, I'll have a go at further investigations tonight.
Out of curiosity, does access to the seat back Peltier unit require seat removal from the car or can this be accessed by shunting the seat fully forward and tipping the backrest forward and removing the hard shell rear cover?

 

[RPSN]

I’ve attached the relevant TOPIx documents for vehicles with sports seats and for vehicles with performance seats.

Also, information on how to make the Supplementary Restraint System (SRS) safe before working on or in the vicinity of SRS components.