Does anyone know what the little square { 3/4 in.] with a small glass lens in the middle of the dash about under the rear view mirror ES300 1994. Can't seem to find any thing in the wners manual. This of course is at the top of the dash on the seam where leather ends.

 

my guess would be the auto-headlight sensor so sense light and darkness.... but im not sure if that year was equipped with them

 

Good thought on it being sensor for headlight dim but if so I don't think it would be aiming at the ceiling.

 

This question was asked before in this forum. I am pretty sure that's the sensor for the master remote key of the ES. The sensor for the headlight auto-on/off feature was equipped after the 1997 ES 300.

 

Thanks, that makes sense

 

It's a light sensor for the climate control, actually. Ever notice how the A/C fan automatically blows harder when driving into the sun? Somebody posted proof of this a while back. The newer cars have two sensors, one for the lights and one for the A/C. The keyless entry uses an antenna in the back glass, and I believe the receiver box is in the trunk wall.

 

It also is what is used to measure the outside temp. It has nothing to do with remote or keys.