Driver's Seat Vibration in a 2012 ES

[veimi]

After reading the thread about the cooling fan coming on from time to time when charging, I thought I should ask the following question.

Shortly after picking up my new used 2012 ES I was sitting in it while in my driveway with the key on and for a few seconds felt a significant vibration in the driver's seat which quickly disappeared.

I was wondering if anyone else had experienced this and what could have occurred to cause it? The vibration was only on the seat bottom and not the seatback. It has not recurred and I'm certain it wasn't my imagination. It was so strong that it felt like there was a mechanical device vibrating in the seat.

I have a friend who has both a Tesla and a Cadillac. I don't know which one has this feature, but I was told that his seat vibrates when some potentially dangerous road situations occur (blind spot?) .

In thinking further about this, while sitting in my driveway I was also investigating the car's controls including the seat heater which I couldn't figure out was on or off. Any possible relationship?

 

[PV1]

We're definitely not that fancy. Was the A/C on? It was likely the compressor you felt.

 

[veimi]

I have added an additional line to the original post regarding the seat heater.

Is there a relay in the seat that turns the seat heater on or off?

If so, it felt like this relay was vibrating.

 

[PV1]

If there even is a relay, it would be under the dash.

 

[veimi]

Found this on another thread.

It appears that the heated seat has a thermostat built in.

There is a single cable (black) running to the heated seat which implies that the thermostat is actually contained in the seat heating module itself.

Knowing this, it now appears to me that the possibility exists that on a hot summer day with me sitting in the seat and playing with the car's controls and the seat heater on, the seat heater thermostat was chattering.