outside temp reading + climate problems

[darko]

im hoping someone can help here - My S3 has been reading the outside temparature wrong for a while on the DIS.

It seems ok 1st thing in the morning, for example leaving home this morning it read +6' and after a mile or two hot air started blowing and heating the cabin up.

After 20 mins the outside temp started climbing - by the time I arrived at work it said it was +21' outside and the climate was blowing ice cold air !

I took the car to Audi who have fitted a new sensor at the front of the car but they insist the outside air temp sensor has nothing to do with the climate control...

Can anyone help on this one - its really getting annoying !

 

[simch]

I am sure it does! In fact it deffo does, its what tells the compressor NOT to turn on at all if the outside temp is less than about 5 degrees, (maybe 3?).

Put it this way, if all it does is make that stupid snowflake come up on the DIS, then what a flippin waste!!
"I know its ****** cold, my *** just fell off!!"

I would check the sensor's wiring too, but it may well be goosed. All a bit vulnerable down there at the front bumper area? (think its there, is on a golf).

 

[simch]

The other sensors on the climate are the in car temp sensor and the sunshine sensor on the base of the screen I think! Not got a real bright tom tom shining on it have you!!

 

[darko]

im 100% too that the outside temp sensor operates the climate or effects it at least - try telling Audi that !

just drove the car now up the road and its reading +16' outside (wish it was !) with 22'c dialled in on the climate control im getting cold air blowing in the car - not comfortable..

the dash sunshine sensor is not covered or being effected by anything other than light through the windscreen, not that theres much sunshine today either..

 

[Secret Squirrel]

That sounds strange. When I had trouble with an ambient temperature sensor, the ambient temperature display was showing anything down to -40°C. But as the ambient temperature decreased, the inside of the car got warmer, as if the climate was trying to compensate for the cold air it thought it was taking in.

 

[madvw]

you've not got an FMIC or any coolant leaking onto the sensor have you?

 

[darko]

no FMIC - no leaks etc, Audi had the whole thing off at the front replaced clips and had the Air con totally refitted at the front of the car, the fixed the LH head light washer which was stuck and resprayed the bumper - I was very happy with the service and quality of work but just seem to have got stuck on this temp sensor problem

I might have to have a look myself - the Audi bodyshop are speaking to the workshop (seperate building) and have aksed me to call back this afternoon for an update

 

[simch]

Audi probly fitted the new one in the header tank for you! Stops it Icing over!! lol!

Does Vagcome say anything about a sensor fault? I'd certainly check the wiring to it, one dodgy earth there and it could make things go real haywire!

Surely its too much of a coincidence to have a dodgy outside airtemp AND dodgy climate too? Must be connected.

BTW, did audi actually fit a new sensor, or did they tell you it was not connected to climate so you did not bother?
If they fitted a new sensor, first thing, take it back to them as they have not fixed the "OUTSIDE AIR TEMP" problem you took it in with.
At least get the cash refunded or get them to do more to fix it! I am sure once its put right, the climate will miraculously recover much to audi's surprise!
I think if you go and search on UKmkiv.net, there is a thread about climate control and why it does nto turn on in the cold conditions.

 

[darko]

they have told me there was no sensor fitted so they fitted a new one - very weird, surely if there was no sensor fitte dthere would be no reading or a fixed reading of some sort

the sensor does change reading (and did before i took the car in) but the range is out

i have an understanding of electronics and would agree that a bad earth would effect resistance etc and throw the reading out - its strange though, like the engine temp is effecting the sensor - when the car is cold in the morning i get an accurate reading, after driving for a bit the reading rises

it makes me think engine heat is escaping into the area of the bumper where the sensor is

 

[Secret Squirrel]

The ambient temperature sensor is located in the N/S lower grille.
Check the climate diagnostic display and have a look at the values, to see if that sheds some light. Channel 5 and 59 maybe of interest.
If you don't know the climate channel codes, click here.

 

[simch]

may have been worht mentioninig the lack of original sensor according to audi!!

Sounds a bit suss!
BUT if there was NOT one fitted, the plug to it could be full of crud and causing an issue. You sure they plugged it in right when fitting the bumper.....everythign else work Ok, fogs etc....?

Vag com it, take it to a specialist not a bunch off muppet dealers....! !

 

[darko]

I would have mentioned the missing sensor earlier except Audi only told me that today - I know the sensor wasnt missing, they are just scrabbling for answers, I have to phone them in 1 hour for an update anyway..

 

[darko]

have just spoken to Audi and they are now saying it could be many things such as: low radiator water level, air lock in the aircon system or another sensor - madness... i will have to book it back in to have them investigate it

thinking i might look up a specialist, thing is i have actually paid for this to be fixed !

 

[Daniel Vzla]

I have the same issue but does'nt affect the climate control in my A3, here the average temp is 23-25°C but the temp displayes in the DIS is normally around 39-31°C :S:S

 

[Jameswmcl]

I have similar issues on my 97 A4 1.9 TDI - is the sensor easily replaced.?

 

[jonS3]

i'm glad i've found this thread.

my outside temp reading is going crazy at the moment and is currently down at -45c which according to this thread makes the air con stop working, which mine is doing. i've just put 2 and 2 together.

I think this is the answer:

OBD Channel 52 - A/C Compressor switch-off codes

If an A/C compressor switch-off condition exists, a segment of the "88.8" display, indicated below as an alpha-numeric code, will illuminate.

Segment Condition
a1 Slippage or blockage, A/C Refrigerant High Pressure Switch, 120x off
b1 Engine Speed (RPM) less than 200 - 500
c1 Engine Speed (RPM) greater than 6000
d1 Engine Speed (RPM) greater than 6000
e1 System function OK
f1 System function OK
a2 A/C manually switched off (A/C standby canceled)
b2 low voltage
c2 Kick-down switch, compressor off for 12secs max.
d2 Engine Coolant Temperature (ECT) warning light switched
e2 A/C Refrigerant Low Pressure Switch (F73)
f2 A/C Refrigerant High Pressure Switch (F118)
a3 ECON mode selected
b3 OFF selected
c3 Outside (ambient) temperature too low
d3 Engine management system (compressor will remain off for 3 -12 seconds)
e3 High pressure occurrences more than 30 times
f3 Ambient Temperature Sensor at Fresh Air Blower (G109) less than 27 degF (-3 degC)
g1,g2,g3 System function OK (g1+g2+g3 must illuminate simultaneously to indicate system is OK)
Decimal Point
Lit A/C compressor ON
Decimal Point
Unlit A/C compressor OFF

see point C3, this proves for sure that the AC compressor and outside temp sensor are connected

THIS SHOULD REALLY BE A STICKY AS THIS HAS CAUSED ME SO MUCH HASSLE OVER THE LAST YEAR AND COUNTLESS TRIPS TO AUDI WITH NO JOY

 

[B120WNY]

Does anyone know what cable colour or number the external temp sensor is into the back of the climate console? Im retrofitting a DIS dash and need the cable from the external temp sensor in the bumper, which I believe feeds into the climate control panel. I dont really wanna have to route a full cable from the front bumper!
Help most appreciated!

 

[JamesVAG]

That sounds strange. When I had trouble with an ambient temperature sensor, the ambient temperature display was showing anything down to -40°C. But as the ambient temperature decreased, the inside of the car got warmer, as if the climate was trying to compensate for the cold air it thought it was taking in.

Did you ever get this sorted?

 

[hydro s3]

Just read this and never knew that there is a sunshine sensor at the bottom of the windscreen. I have looked and don't seem to be able to find mine. Could anyone shead some light on where it is?