Seat Heater not turning off.
 

I have a '03 4runner limited with front heated seats. Yesterday for some reason my driver side seat started to heat up with the switch in the off position. It got so hot I thought the seat might catch fire. As soon as the seat got that hot, something triggered it to turn off. It eventually cooled down again. This problem just started so I haven't had a moment to look into it, but wanted to see if anyone had a similar problem and could tell me where to look. I plan to pull the fuse for now until I can either fix it or take it in for service.

I have not had this specific problem, but I do have a seat heater issue. I'm getting no heat to my driver's side seat.

Both my on/off switch and the heating element work fine, but my mechanic traced the problem to the seat heater control sub-assembly. You may want to check this on your 4Runner.

Toyota part number is 87501-60010.

I've suddenly started having this issue. I even pulled the fuse & still it gets hot!? Demonic possession????

Did you ever figure this out?

The seat heating system is controlled by 2 fuses.
The seat heater fuse controls the heating elements and the seat heater console switches are controlled by IG1 fuse in the interior cabin fuse box.

Wiring path attached from Factory service manual for '03-'05

A lot of devices on the vehicle are tied into the IG1 fuse- A/C, 4WD, Taillight, etc - so don't pull that fuse because you'll lose these features.

I would look for shorted wiring or burnt connectors first before buying any parts. Start at the console switches (remove console cover) and follow the wiring to underneath the seats.

The part number for the seat heater controller has been updated and should be
875010E020

Please post an update when you get it fixed.

2016 4 Runner passenger seat heater comes on by its own
 

We bought a new 2016 4 Runner last April 2016 and have 2 problems now. Passenger seat heater and liftgate shocks broke. Now 1 year later we have both rear lift gate shocks bad and on order under warranty from local Hickory, NC Toyota dealership waiting for those to arrive to be installed. .

But worse problem, is around same time, the passenger seat heater comes on at full intensity, with control in off position, while driving down the road and has done this several times already. However, the dealership (Johnson) refuses to troubleshoot or do anything about it UNLESS they first visually see this happen themselves! They tell us Toyota requires a visual first before they can do any warranty repair??

Has anyone else had this happen to a brand new 4 runner out there? I am a professional troubleshooter in my profession, and to hear dealership say this is assanine! Recently again, our youngest son was driving and I was passenger, and all of sudden, the darn seat got so hot underneath me, yet control dial in off position, but it was lighted up as it it were turned "on"... When we turned in to park car and shut off engine, one restarted it went off...?

I have a 2016 trail premium, driving up on a road trip somehow the seat heater turned on and wont turn off. I'm out in the boonies so I'm wondering if someone can help me fix the problem. Otherwise I have to drive back with my butt toasting for 3 hours till I get to my dealer who will probably be closed for labor day. help please

Nevermind. Just checked it this morning and it's back to normal. I think we spilled water on that area last night and now it dried out.

That would have been horrible during these hot summer months! Glad it got fixed for you!

wow. super old thread with not much activity. but, I have had this happen on my 06 also. at first, I thought I was just imagining it, but the seat felt warmer than normal for a short period. it did it probably 5-6 times. but its been quite a long time since it happened last. I never did look further into it.

Same issue with driver seat overheating when turned off
 

We are having the same issue with our 2016 4runner with the driver heated seat turning on and getting extremely hot. Similar to HandySteve in Hickory, dealer says nothing they can do unless we can replicate. Has anyone found out anything?

Same issue in '13 model
 

I have a 2013 Limited where the driver seat warmer turns on upon engine start as well. Took it to the dealership and had the electrical guru take a look at it and he said that in 99.9% of these cases, it's the switch failing due to spilling something on them that was in the cup holder adjacent to it.

They were going to charge me $86.38 for a replacement and another $260 for installation. I found the part at https://www.toyotapartsdeal.com/ for about $15 less and the install took about 5 minutes.

If that solves anyone's problems, awesome! It didn't fix mine so I'm still troubleshooting.

Seat warmer not turning off, burning smell 2013 4runner
 

So we figured out the culprit! Under the seat, there is a small black box component under the seat that was getting incredibly hot. It was two plugs and two snaps to remove it and upon further inspection, the internals were fried. The Toyota part no. on the component is 87501-60050 and upon further research with Toyota, 87501-60040 replaces this piece. Here is a link for the piece:

https://parts.toyotaoftampabay.com/o...rol-8750160040

I have one on order and am going to replace the switch (84751-35110) as well in case it was sending a bad signal to make the controller overheat. Hope this helps any one else!

My 4Runner has heated leather seats. They have quit working, but my Toyota dealer said they didn't come with heated seats. Is this true?

I have leather heated seats. Your dealership rep is a moron.