ChuckinTucson

The outside temp indicator on my 05 C230 consistently reads 2 degrees hotter than what the actual temperature is. Is there anyway to have this adjusted?

amdeutsch

Ambient temperature as listed in the news, etc is not measured inches of the asphalt.

ChuckinTucson

Agreed; however, I have a friend with an '07 C230 that reads two degrees lower than my car even if we're driving side-by-side; and my other car also reads two degrees lower than my MB.

e1000

The dealer can correct the temperature on request.

BF_JC230

My wife's 2005 C230 is TODAY reading [-40] when it is +80 outside. I recall this is a BAD ambiet / outside temerature sensor (located under / near the curb side fog light)...

Is this true? Bad sensor?
Thanks,
Jake

Emin

Jake, your sensor is gone. When the sensor is broken, the computer says -40.

As far as the 2 degrees go, how do you know what the actual temperature is?

Dingleberry

my '02 consistently reads 8 degrees higher than actual temperature.

/rant

LILBENZ230

Yep Jake. Scott on here hit a creature and destroyed his sensor and his car now reads -40F as well. Mine sticks sometimes at 77F.

BF_JC230

Upon inspection, loose inspection with a flashlight, looking under the sensor...it appears that the actual grounding wire has pulled out of the connector! Looking at it, it makes NO SENSE how this would "just happen", and the bottom of the car has three, maybe four light surface scratches...this car has never been curbed, or bottomed out!

The brown wire is just hanging out, with a few strands of fresh copper exposed!

- I also have no "fur" around or in the fog light grille!

Does the ECU use this data to help air / fuel mix, or is it ONLY using the IAT (Incoming Air Temperature) sensor in the intake?

Looks like an EASY fix (well, now that I have to FIX the wire harness) as to REPLACE the sensor, you just pull off the inner fender lining.

Dang,
Jake

LILBENZ230

I don't think it has any function other than driver information. The sensor being destroyed on Scott's car didn't have any drivability affect that he mentioned.

Cintoman

My car's temp is always reading a good 5 degrees hotter than what my other car and local bank signs have for outside temp. Dealership replaced the sensor, but it didn't help. I have heard that because the sensor is so close to the ground, and because low to the ground is warmer, that's why the reading is higher.

Cintoman

BF_JC230

Thanks all!,

My wife noted no change in drivability or MPG...So the ambient sensor must not feed the engine ECU.

Here are two pictures, and I am sorry, the disconnected wire (MYSTERY!) did not want to photograph well. The second shot shows what little scuffing there is on the car...no sign of impact, curbing or otherwise.

Thanks,
Jake

bdgdl08

When my wiring went bad (rats my a$$), it made my A/C go bad. I was told (granted this is the worst dealership in the world) that this was due to the ambient light sensor.

LILBENZ230

I can't possibly see what ambient light would have to do with the A/C. Did you mean ambient temp? I would have just assumed that's what you meant but given your experience with that dealer, nothing would surprise me. Either way, a bad ambient temp sensor should have no affect on the HVAC.

e1000

I'm pretty sure they can "correct" the temperature at the dealership

ATL_MB

There is an ambient light sensor that adjusts the A/C -- it is meant (I assume) to adjust for sunlight in the cabin, which heats the cabin much faster than just ambient air temperature.

bdgdl08

I did mean ambient temp sensor...sorry, long day.

LILBENZ230

The "sun sensor" doesn't exist on my 2005 or Drew's 2007 car. I think it's just a placeholder. My car has an ambient light sensor (it adjusts brightness of things during the day, visibly noticeable) but has no affect on the A/C. On pre-facelift cars with digital HVAC controls, though, there was a sun sensor that did adjust A/C.

Glyn M Ruck

Only cars fitted with Thermotronic AC have the sun sensor & can put out more cold air on the hot side of the car. Thermatic can't do this.

endri sallata

mine reads 185 f?

bdgdl08

I think you have a problem... either your temp sensor is broken, or you're going to die.

LILBENZ230

Definitely a problem. "going to die"

samaritrey

wow either it died or is unplugged. they are cheap so go buy a new one less than $20.

zcurtis00

I know this can't really get anymore off topic, but does anyone else think that disconnected wire looks like a bug?

bdgdl08

LMAO, it looks like a creepy *** bug trying to crawl out of there.