yardie876

Same here. I remember reading a while back that the seat heater control module was changed out some time during the MY '13 in 2012.

fuddyduddy

My 2013 GS with luxury package always resets them to off after I turn the car off. Earlier I changed the setting via Carista so that they would not automatically reduce when driving. Mine was manufactured in December 2011, so I probably have the early version of the module if there was a change.

4GS350

My driver seat heater turns on by itself. You can feel the heat on the lumbar area but the indicator switch light is still off. Anyone encountered the same scenario? Lux package.

bclexus

@4GS350 - This is an old thread you brought back to life! But that's okay because it's still very relevant.

Your driver seat heater control was/is set to 'Auto'. A lot of people don't really understand how the seat heater 'Auto' feature works.

Here's how it works:

When the seat heater console control is set to 'Auto' (one green light is lit beside AUTO) next to the seat heater console control the seat heater will automatically turn On (indicated by an orange light) and will automatically adjust the seat's heat intensity level based on the temperature setting of the HVAC system. Either one, two or three green lights under the Auto' green light indicates the intensity level of the seat heater. When the seat heater is in 'Auto' - the higher you increase the HVAC temperature for cabin comfort the more green lights will be displayed beside the seat heater console control under the Auto' green light to indicate the intensity level.

For example, if you get into your car and start it with the seat heater in 'Auto' (one green light is lit beside AUTO) next to on the seat heater console control - and the HVAC temperature setting is set higher than the cabin's current ambient temperature, two things will happen - (1) the HVAC will increase the cabin temperature and (2) the seat heater will automatically turn On to provide occupant comfort.

Accordingly, the higher the HVAC temperature is set for the cabin - the higher the seat temperature intensity level will increase. Likewise, the seat heater will automatically decrease in intensity level and the number of green lights (under the 'Auto' green light) will reduce as the cabin temperature reaches the HVAC's set point temperature.

Appropriately, with the seat heater in 'Auto' there will be no seat heating if/when the cabin's temperature matches or is about the same as the HVAC temperature set point, because both cabin HVAC temperature and seat heating have become satisfied. But by increasing the HVAC temperature set point significantly higher, this will 'automatically' turn On the seat heater (indicated by an orange light) - and the higher the HVAC setpoint, the higher the seat heat intensity level becomes and the more green lights will be displayed beside the seat heater console control (under the 'Auto' green light).

► An Orange light indicates the seat heater has been energized and Green light(s) under the AUTO green light indicates the seat's heat intensity level.

The same scenario applies to the passenger seat with applicable HVAC temperature setting for the passenger side. As such, the rear seat heating for the Lux package works in the same manner.

Whatever setting was last used (e.g. 'Auto' or a manual setting), it will be retained when restarting the car...unless a change has been made with LPS or with the Carista app.

4GS350

Thank you very much for the detail explanation . I checked my settings and found it wasn't on auto. I am currently facing a potentially faulty servo motor though and suspect it may be causing the seat heaters to go cranky. Planning to change the servo motor in the coming couple weeks.

bclexus

Now that my climate here in Dallas is no longer triple-digits but instead in the 30s and 40s overnight I love how the AUTO feature of seat heaters works perfectly in conjunction with the set point temperature of the car's HVAC system.

bclexus

► There is one additional factor used in determining the intensity (number of green lights) of the seat heating when in AUTO mode:

The seat heat intensity level (number of green lights) is linked not only to the HVAC cabin temperature setpoint setting, but it is also linked to the outside temperature - the difference between the HVAC cabin setpoint temperature setting and the outside temperature.

If you raise the HVAC cabin setpoint temperature you will see the number of green lights increase. Likewise, the colder the outside temperature difference is compared to the HVAC cabin setpoint temperature, the more green lights will be displayed.