Heated Seat Issue

[Arm]

Hello,

I have a 2019 i3s that has as an issue with the heated seat on the driver's side. When I press the button, the lights come on for perhaps a few seconds (you hear the solenoid or relay click), then it turns off (and you hear the click again). It will not come back on after that unless I reset the vehicle (turn off and restart).

Has anyone experienced this?

Thank you.

 

[jadnashuanh]

I've not, but it sounds like you have a short, and the overload is tripped. From your description, it sounds like it self-resets, but only upon a vehicle power up.

Other than checking the plug is fully inserted under the seat, it sounds like a trip to the dealership.

 

[tman66]

Hello,

I have a 2019 i3s that has as an issue with the heated seat on the driver's side. When I press the button, the lights come on for perhaps a few seconds (you hear the solenoid or relay click), then it turns off (and you hear the click again). It will not come back on after that unless I reset the vehicle (turn off and restart).

Has anyone experienced this?

Thank you.

I have the same issue and on the same side. Mine is a 2014. I'd agree that it's a short. I would take it to the dealer and can you please report what they find? I'd love to fix mine without a trip to the dealer.

 

[Arm]

Hello,

I have a 2019 i3s that has as an issue with the heated seat on the driver's side. When I press the button, the lights come on for perhaps a few seconds (you hear the solenoid or relay click), then it turns off (and you hear the click again). It will not come back on after that unless I reset the vehicle (turn off and restart).

Has anyone experienced this?

Thank you.

I have the same issue and on the same side. Mine is a 2014. I'd agree that it's a short. I would take it to the dealer and can you please report what they find? I'd love to fix mine without a trip to the dealer.

Ok will do...took it in today...won't get it until early next week.

 

[Arm]

Hello.

As promised I wanted to give you an update.

So I got the car back and the service tech found the following:

FAULT 804613 SEAT HEATING: DRIVER BACKREST HEATING PAD LINE OR SHORT BREAK TO B+; FOUND DRIVER SIDE SEAT HEATER FAULTY
(D5210_00000000_66_001)

REPLACED DRIVER SEAT HEATING ELECTRONICS.

Hope that helps

 

[RiendeJonge]

De verwarming van bestuurderszitting van mijn i3 viel al een tijdje steeds na 3 minuten uit. De auto gaf geen storing aan. In het volle vertrouwen op BMW zag ik het een tijdje aan. een storingsmelding bleef uit. Afspraak bij de dealer voor een analyse. Uw zitting heeft kortsluiting. Moet vervangen. Kosten 400,,--. Bij controle op de kapotte zitting bleek de aansluiting van de 12v kabel gebroken. Te weinig flexibel/te kort.

 

[ronin]

I just started having this problem intermittently. It looks like the element and seat cushion are one piece and there is also a seat module. Both can be tested with a multimeter.

https://www.youtube.com/watch?v=CgL37CQNcWc

 

[eNate]

De verwarming van bestuurderszitting van mijn i3 viel al een tijdje steeds na 3 minuten uit. De auto gaf geen storing aan. In het volle vertrouwen op BMW zag ik het een tijdje aan. een storingsmelding bleef uit. Afspraak bij de dealer voor een analyse. Uw zitting heeft kortsluiting. Moet vervangen. Kosten 400,,--. Bij controle op de kapotte zitting bleek de aansluiting van de 12v kabel gebroken. Te weinig flexibel/te kort.

The heating of the driver's seat of my i3 has been switched off after 3 minutes. The car did not indicate a malfunction. In full confidence in BMW, I saw it for a while. an error message was not received. Appointment at the dealer for an analysis. Your seat has a short circuit. Must replace. Costs 400 ,, -. When checking the broken seat, the connection of the 12v cable was broken. Too little flexible / too short.

 

[tman66]

Hello.

As promised I wanted to give you an update.

So I got the car back and the service tech found the following:

FAULT 804613 SEAT HEATING: DRIVER BACKREST HEATING PAD LINE OR SHORT BREAK TO B+; FOUND DRIVER SIDE SEAT HEATER FAULTY
(D5210_00000000_66_001)

REPLACED DRIVER SEAT HEATING ELECTRONICS.

Hope that helps

Hi. Thanks for posting this. I don't suppose you know what Heating Electronics he was referring to?

 

[Arm]

No unfortunately I've no other information regarding what they did.

 

[ronin]

I need to take my car in for an oil change and will get a detailed estimate to repair the seat including time and materials.

Mine stays on for about 3 minutes, gets very hot and then shuts itself off.

I was going to swap the ecu’s under the seats but I’m guessing it’s temp sensor related and requires replacement of the entire foam seat cushion.

 

[ronin]

The notes from my dealers state: fault code 804906 passenger seat heating line break, ran test plan, test plan failed passenger seat heating grid. The quote for replacement comes out to $1,386.22. That's ridiculous. Granted my car is a 2014 but it only has 32,000 miles and I rarely have passengers let alone using the seat heater.

 

[Grobian]

Had an issue with our used i3, which was present when we rolled off the dealer lot. The driver side seat heating would turn off after about one minute, and would refuse to turn on until the car had been restarted. The dealer replaced the heating mat in the seat, and the problem has disappeared. 94Ah 2017.

 

[ronin]

I spoke to a tech about it one has to order the entire seat cushion which has the "heater mat" and the temp control integrated into it. The part is about $160 or you can buy the cushion with the fabric already attached for about $600.

 

[rtanov]

Just finished replacing my driver's seat cushion and have some observations and pictures to share. My seat heater was coming on fine but would turn off after 3 min and will not turn on until the car is turned off and on, and a few minutes have passed. I had a broken temperature sensor. I believe if yours comes on and goes off after only a few seconds this is an indication that you have a broken heating element not the sensor. They both require same part and work to replace - just replace the seat cushion with the heater & sensor integrated (assuming the seat not the back is the problem) - part # 52-10-7-388-647 - Seat Cushion Pad Left for driver seat. Cheapest OEM I found was at my local dealer who is selling parts online with local pick up - total cost $170. https://www.thebmwminipartstore.com/

I used the Youtube video referred on the first page of this thread for instructions - work is not hard - taking the seat off the car is much easier that other seats I've worked on since it is lighter and the lack of B-pillar helps a lot. Taking the cushion out is not hard but annoying and time consuming. I think it's best to get a good cutter and just cut the metal clamps as they will be very hard to reuse. Just get two dozens of small plastic ties - they work very well - this is what the guy in the Youtube video does too. Threading the ties under the seat cushion wire is hard initially but as you progress it becomes easy. Just make sure you orient them so that you'd be able to tighten and cut them as you progress in the assembly process.

To get the seat off the car you need to disconnect the seat power supply - this is very easy but if the car is not completely off it will trigger an airbag warning that needs a special tool to erase. I wasn't worried about this as I do have the tool - I just turned the car off but when the door is open the instrument cluster has the BMW logo on it. After I put the seat back and reconnected everything the airbag warning was triggered and I had to clear it. I believe you'd have to wait for the car to go into sleep or remove the battery to make sure the warning is not triggered if you don't have a tool to clear it.

I peeled the heater off the cushion where the temperature sensor sits on my old cushion just to see where the problem was. I took some pictures that might be helpful if someone wants to fix it rather than buy a new cushion - it seems an easy fix in my case. If I have to do it again I would first try to fix mostly because I like to revive thigs rather than throwing them away. The guy in the Youtube video shows how to measure the resistance of the heaters to diagnose the problem. There are three wires coming out of the plug - brown, green/purple, and black. The green/purple splits into green and gray before it gets into the cushion - the green one goes to the heater, the gray one to the sensor - this picture shows the wires:

https://photos.app.goo.gl/4YQayW368aRC9zBu5
I measured the resistance of the new cushion at the plug between the black and green/purple - it was around 10 kOhms, bad one was zero as the black wire was broken. Here is where I had to peel the heater pad to get to the sensor:

https://photos.app.goo.gl/2TCMmKpKUsyo2chX8
Here is the sensor from underneath the pad - the sensor is still inside the pad - you can see the two yellow wires leading to it:

https://photos.app.goo.gl/vHyxqwGiAT6Mky7RA
And here is where my black wire was broken:

https://photos.app.goo.gl/tmzfJ2sMP1fvwP5f7
This must be a weak spot as you can see that the gray wire has the insulation broken too. It seems it would be easy to replace these with new pieces of wire.

Hope this helps others to diagnose and fix these problems. Cheers.

 

[BobbyC]

After reading all the information here and on the internet about the heated seat not working due to a broken temperature sensor, I fixed mine without having to spend any money. I found an easy way to access the broken wire and repair it. I had both the grey and black wires broken. It looks like a design fault with the i3 and if BMW hasn't fixed it yet, I am certain it will happen eventually to everyone at some point if you plan on sitting in your seat.

The actual temperature sensor wires (yellow wires) are much thinner (probably 22 gauge) than the grey and black wires (prob 18 gauge) and yet the broken wire(s) will definitely be the grey or black or both. The chances of failure increases with the number of times you sit in the seat. This is because BMW placed these wires (and not the yellow wires) under the metal rod that spans across the seat and into a groove in the seat cushion. This metal rod is "tied" to another metal rod that is in the seat to hold the cushion down and probably acts like a spring for seat. As you sit in your seat, the set the wires are pushed down into the groove by the rods most likely exceeding the bend radius. Then when you get up, the wires are pulled back up. It is this repetitive motion that causes the eventual break(s). The break for my wires are right at where the wires goes into the groove at the metal rod.

I was able to fix this in about 1 hour, without taking the seat out or removing the cushion or any other hardware. I was able to partially remove the cover by "unclipping" the seat cover from the back underside and roll the cover through the seat and expose enough of the cushion where the sensor is located. This takes only about 10 minutes. I had to cut only 1 of the metal clip instead of all of them to access the broken wires. Later I used a plastic tie after repairing the wire. I also cut a small hole in the part of the seat cover liner just above the metal rod but not in the leather so that the wires for the sensor can pass through OVER the rod and not under the rod. This should prevent the wires from getting broken from repeated seating.

I also wanted to thank everyone who posted their experiences and tips as without them I would not have been able to figure out this easy way of fixing my heated seat.

 

[BobbyC]

I've created a step by step guide on how to repair your seat if you have the temperature sensor (thermistor) issue. I believe this is the cheapest and easiest fix that is better than the original as it also corrects the design flaw so this won't happen again. Enjoy!

https://drive.google.com/file/d/1Oxqk3veP-bl2xnk71GEovtDFTda83pCC/view?usp=sharing

 

[Arm]

Thank you for posting all that!

 

[Houdini56]

Thank u very much for this info..it totally makes sense about the logistics and thin wire…do you think an auto electrician with these instructions can repair? My bmw service people asking for $2000…also the knob with the fan direction on it..face..feet or straight..has ceased to light up..but it still operates with a bit of guesswork..anyone fixed or encountered this..easy to fix?

 

[Paul4A]

That $2000 sounds like robbery. Wisely Automotive in London charge only £383 for completely replacing the seat base. See their pricing schedule linked on their latest YouTube video