e60bmw

iTrader: (1)

I'm hoping someone can help me on this one, because its driving me crazy. For some reason my heated seats have a mind of its own, they seem to always come on when I don't. In fact when they come on the light for the heated seats you normally press isn't on. Now I thought maybe this is related to eco mode however it happens in sport mode, I always set it to sport mode. I've checked everywhere in settings to see if this is a feature that can be turned off. Do you think this is some sort of malfunction or anything that I can do about it? I hate having them come on automatically even when its not even cold outside! I try messing with lowering the temp not using auto temp and everything.

bclexus

You say the heated seats turn On unexpectedly, but their indicator lights are not lit. Even if the heated seats do automatically turn On (with a trigger from some sensor) it makes no sense that the indicator lights do not signal that they are On. I'm not aware of any sensor or control (e.g. thermistor) that would trigger the heated seats to automatically turn On. I have never heard of this happening. Are you absolutely sure the heated seats are really On?

e60bmw

iTrader: (1)

Yes my back and butt are all heated up, they come on almost instantly. The heated seat light shows nothing.

rijc99

Are you sure you don't have your heated/cooled seats set to Auto?

bclexus

Is that the case for both front seats?

mcomer

What response do you get when you press the Ventilating side of the control?
Do you get 1-2-3 lights and a fan blowing noise and shortly after a chill wind?
Let's check on the lights and connections by trying that. Then you should try
the actual Heat side and watch for 1-2-3 lights. Is the seat now just as warm
or warmer than when the lights are not on. Are these symptoms on both seats?

rijc99 - Auto seats were not on the first year 2013 GS BTW

e60bmw

iTrader: (1)

<br />I noticed earlier when I turned on the AC seats they came on but the seat still felt hot as if they were both on. I just tried passenger side, and there is no issue there, it cools and there is no heat. I noticed sitting next to the drivers seat with the engine on the seat is heating up as if its on max heat but there is no heated light on and I'm not even sitting in it. I don't know if disconnecting the battery for 15 minutes would do anything or maybe even checking fuses.

bclexus

Just so you know, the seats are not cooled (as in with A/C). They are ventilated. This ventilation is merely piping the car's interior air temperature (near the floor) into and through the seats. If the car is hot from being parked outside on a hot day, or sitting directly in the sun, the seat ventilation will pipe this warm/hot interior air into and through the seat. The advantage of ventilated seats is using it 'after' the interior is already cooled with the A/C, thus the seats are ventilated with cool interior air.

bclexus

You never said, but 'if' you have a rear air conditioning system - when the front seat heaters and ventilators/rear seat heaters are set to “AUTO” mode, the system is operated automatically according to the set temperature, outside temperature, etc.

If you are checking (testing) the seats with the car outside, you are likely getting false information due to the sun and radiant heating. It would be best to test the seats with the car parked in a shaded garage, or some other similar area, after it has been sitting for awhile. If you have a thermometer you should be able to easily determine when the seat heaters are energized...and whether you really have a problem, or not.

e60bmw

iTrader: (1)

Its about 80 degrees outside and they come on. I even disconnected the battery and still have the problem, you can feel it heating up more as you sit on the seat even when it was just in the shade and the seat was not hot prior to starting the car. Theres definitely a issue, I just can't think of what could cause it. The fuse shown in the owners manual is tied to several other things that are working, so the fuse really isn't going to do much most likley.

bclexus

It sounds like the seat heaters are permanently wired (or back-wired) to a switched hot (12 volt) circuit, where the seat heaters are provided voltage all the time whenever the accessories are On.

I'm curious - was the car bought from a Lexus dealer as a CPO?

e60bmw

iTrader: (1)

Guess the car is already starting to strike, it was previously a flood car. So I assume it jacked up the connection some how. Its really just the heating thats the issue, it seems to fade sometimes as I drive it too. The cooling works fine. It feels like it auto adjusts somehow, however no settings like that anywhere. This car has the cold weather package.

bclexus

Well, well...a flood car...oh boy. Okay, the seats were almost certainly removed and there was likely some damaged or destroyed wiring/connectors and the installer wired the seat heaters to a switched 12 volt source instead of wiring them correctly through the appropriate switches on the console. It does not surprise me that the seat heaters auto adjust (fade) down - probably because of a thermistor located near the seat heating mats.

This may be a 'one-off' gremlin, but be prepared to find other 'issues' since the car is a flood-damaged vehicle. It was previously a flood car...and it still is a flood-damaged car...

Dallasguy1

So did u know it was a flood damage with salvage title or is it clean title and u just found out , in any case I would just take the fuse out and disable the whole heating thing since your in Texas and I'm sure don't really need them anyways.

e60bmw

iTrader: (1)

I realize this is a one-off issue, its more of understand what to look for. Info on specific stuff like this is hard to come by in my research for the car being pretty new. The most important thing the drivetrain is really strong on the car. The wiring harnesses are all in place, not sure if you know but would the heating element be the white connector on the right side of the seat if I'm sitting in it? It looks to me that there are only 3 connectors in the front, I don't know if there are others that could be disconnected. Disconnecting the other connectors results in a airbag warning which is good to show its working, and then the other one is for seat adjustment. The white one I'm not sure what its for exactly, didn't seem to have a effect on the seat heating. There doesn't appear to have been any wiring modification.


Of course, I paid $16k for this car, and this is really the only issue thats been bothering me thus far. I saved so much on the car that I had room for stuff that needs replacement. Its not for everyone obviously but I took the risk. I would remove the fuse, however the fuse in the manual showed as also controlling some other stuff RH-IG(Tensioner reducer, seat heater/vent switches AWD system, front right hand door ECU etc) Unless I'm looking at the wrong switch in the manual.