My annual safety inspection is coming up and in Virginia we have those lovely yellow stickers displayed right at the bottom center of our windshield.

Now this is kind of a silly question, but the current location that the sticker is in covers up my CC sensor on the dash. Is that a big deal? I was thinking of having them move the sticker over about 3 or 4 inches to allow the sun to hit the sensor, but I'm curious as to whether my request is necessary or not. Does the sensor affect fan speed or the air temperature, or both? I'm still not totally sure how it works. Any input? Thanks.

-Shaun

 

I think the on top dash sensor is for the sun and affects the dash lights. When they come on, dimming, etc.

 

I'm talking about the round sensor in the center of the dash, right at the front center near the windshield. It's called a sun load sensor and it affects the automatic climate control somehow.

 

You don't say if you have a navi or not. The navi unit has a sun position calculator that refines the auto climate control...the non-navi does not. Given the following note in the troubleshooting guide of the service manual, I'd certainly have them move the sticker:

(Sumarizing)

Sensor Input Display Mode: Sensor 3 : Solar Radiation Sensor Value: Dark = 00, Flashlight = 04, Cloudy = 10, Sunny = 65

(End)

I'd say either climate control unit would be less efficient with the sensor blocked somewhat...the navi a little less than the non-navi. I found the sun position trick in the navi troubleshooting mode...it's kinda fuun to have the system show how many and what satellites it can see...

 

I've never considered this, and I have my VA sticker right in the middle where they always put it. I do have a navi, and I cannot say I've noticed any problems with my climate control, sunny or not.

 

I don't believe the sun information is used on the Navi. There's some passage in the '04 Shop Guide that says this information is not used for the TSX. I'm too lazy to go get the exact passage. Apparently that screen in the diagnostics is a left over from some other model.

 

Both models on the '04 have the sun sensor according to the Shop Guide. It's not dependent on Navi vs Non Navi and the shop guide only provides 2 voltage ranges.

 

I don't believe the sun information (Solar Angle) is used on the Navi. There's some passage in the TSX Service Manual 2004 that says this information is not used for the TSX.

The sensor you are referring to in the center of the dash is a Sunlight Sensor and it appears in the section with Climate Control.

There's not much detail on what it does or what it affects - I suspect it adjusts the AC based on the sun load.

Readings should be 3.6-3.7V or more with sensor out of direct sunlight
3.3-3.5V or less with sensor in the sun. There is no disclaimer in the guide on Navi vs Non Navi so all vehicles have this sensor.

Details on this sensor are on page 21-62 of the same TSX Service Manual 2004.

 

Thanks for all the replies. The reason I was asking about this is because normally wherever I'm at (in the car, at home etc) I like the temp to be around 75, but in the last few days when it's been in the 70s and 80s outside I've had to set the auto climate to 65 to be comfortable. It just doesn't seem like the air blows out of the vents much when the sun is beating down on me. Somewhere along the line I read that the sun sensor on the dash affects temperature and fan speed of the climate control, but if the inspection sticker blocks sunlight from hitting it, the sensor might as well be useless. Also, I have Navi if that makes a difference.

-Shaun

-Shaun

 

I don't "know" if the Navi makes a real difference with it's sun position data (just thought I'd mention it)...but I do know the sun sensor is used to calculate the extra cooling needed to get the effect of the select temperature despite the sun beating down. Given this, I'd definately move the sticker...it certainly will cause a weaker air flow to the upper vents on sunny days than would normally be provided.

 

I stand corrected on the Sunlight sensor. It IS for the climate control..........