air con

[merc man]

hi there all
i have some sort of problem with my air con system, i know its cold but the temp reading shown on my dash is -40 which by any standard is not correct, also the heater does not seem to blow hot air out. The car has to be warmed up and driven for about half an hour before i even get a glimpse of warm air and does it quite weakly even on the highest setting. but when i turn on the windscreen de-mister it seems to blow at full blast and clears the windscreen in seconds. i have checked all the fuses and looked for any debris ect. I replaced the thermometer/sensor on the front bumper grille but no luck. could this be a coding issue because i had some coding done a while back and some coding was done as the temp reading when on the star was hotter than the sun! any advice would be a great help as im feezing my bits off in this weather!

 

[merc man]

anyone??

 

[Diesel Benz]

The -40 degree reading sounds like an issue with the temperature sensor at the bumper. Perhaps it isn't the sensor itself if you replaced it already (with a new one). I cannot see a coding issue could be related to this.

If you get good heat with defroster on (did you check that you do get good heat), it does not sound like an issue with the valves controlling hot water circulation.

 

[merc man]

i have replaced the sensor on the bumper with a new one and cleaned the connecting wiring loom, and checked all the fueses ect. i have even sat there with the other halfs hairdrier, the demister does blow hot air but when i use the normal buttons to get the heat, nothing happens till the car is hot or been driving for a while even then its a tricke of hot air, as mentioned before i had some coding done but did not really use the heater function that much in the summer as i was using the CLK,which is perfect in terms of heating ect.

 

[andy27168]

What does the temp. sensor on the bumper have to do with the air-con?
Bumper sensor is only used for the indication of the outside temp. and is displayed on the lower left dial of the cluster.

 

[whitenemesis]

Apparently one can adjust/correct the temp using STAR but only by 3deg!

It is also possible that the control unit requires recoding.

Have you had any error codes read?

Also make sure the centre vents are not directed at the interior temp sensor

 

[merc man]

im going to get the codes read asap, i went in to mercedes who said that they are fully booked for another 2 weeks!! there is a local guy who has 'delear level access' and says he can do adapations and coding but im not sure he knows what he is doing as hes says he can code the new style key if i brought it from ebay, but as many have said, the key can not be recoded so is just a waste of money. anyone local to south london that has a star?

 

[whitenemesis]

Try these guys. Not south London but close

 

[merc man]

lol how could i forget !!!!!!!!!! must be the cold freezing my brain. sorry alfie and rich