Any idea what this mysterious sensor is?

OU812

In a 2015 Ford Fiesta.

It's right at the front of the dash in the centre (left to right). Slightly different colour & material to the rest of the dash & can't find any reference to it in the documentation




Forgive the formatting, I'm on mobile

shietpilot

Sun loading sensor for automatic climate control

http://i.imgur.com/hAdgaQZ.jpg

biko

I've one too, fairly sure it's a light sensor (at least on my saab).

colm_mcm

I've one too but if I cover it up the lights don't come on.

shietpilot

colm_mcm wrote: »

I've one too but if I cover it up the lights don't come on.

Surely if you cover it up the lights should come on because it's night time? :rolleyes:

colm_mcm

sorry I mean the one that's in that position on the dash.

Wossack

shietpilot wrote: »

Surely if you cover it up the lights should come on because it's night time? :rolleyes:

no, its like a parrot - you cover it up, and the sensor goes to sleep

GM228

Automatic light sensors are usually behind the rear view mirros and face directly forwards from the glass, sensors on the dash are indeed sunload sensors.

GM228

OSI wrote: »

Google says it's a climate control sensor.

No it is a sunload sensor, but still related to the climate control! The actual climate control sensor (better known as a heater temperature sensor) is under the dashboard.

Sunload sensors are usually like the one pictured or a coloured flat disc in the centre of the dash near the windscreen.

They monitor the intensity of sunlight and adjust the climate control to improve the comfort level.

The technical part for those who are interested:-

Most sunload sensors are the photodiode type, which provides increased resistance as the light intensity increases, so the signal from the sensor drops as the sun shines brighter. The operating range is between 0 and 5 volts. As the sun load increases, the voltage decreases. The signal is sent to the unified meter and A/C amp, which provide instructions to the climate control system to adjust fan speed etc.

OU812

Thanks folks !

hi5

Photovoltaic sensor.

kirving

The climate control system will definitely have a temperature sensor and generally a humidity sensor too. Humid air feels hotter or colder against your skin because the water content in the air has the ability to store and conduct heat better than completely dry air alone. The aim of the climate control system will be to set the cabin to say 20°C, but also to make it feel 20°C.
There is also the issue of not wanting to make the air too dry, as that’s uncomfortable.

The sun load sensor in addition to the other sensors allow the CC to work out that the dash are of the car will heat up more quickly due to the sun through the windscreen, and the top vents can get more cool air to compensate for this. Radiant heat though the windscreen might also make the car feel warmer than it actually is, so the CC can further compensate for this by trying to set the temperature to 18° because 18° in the sunlight feels like 20°C in the shade.

I wonder do cars with a light sensor in the rear view mirror also feed this into the climate control?

biko

I have a Auto setting on my AC and I'd say it uses the dash sensor to determine how hot/cold it should adjust the AC to.

GM228

Kevin Irving wrote: »

I wonder do cars with a light sensor in the rear view mirror also feed this into the climate control?

No the light sensors usually just do lights and auto wipers.