Mercedes CLK external air temperature sensor

digerati

My CLK has been in the body shop for repairs (don't ask...) to the right side. It has had new fenders front and rear, a new wing, door repairs etc. etc.

Since I got it back, the external air temperature (reported next to the speedo) is always wrong -- it tends to overestimate the temperature by about 20 degrees F. When crawling in slow traffic, I see the temperature climbing to over 100F by 1 degree every few seconds when I know it's a steady 80-ish outside. Other times, when coming past San Francisco airport, it shows 68 degrees when I know (from all the other times I've driven past it) that it's low 50s out there in the cold wind.

So... having been without my car for 3 weeks, I don't really want to take it back to the body shop and have them dink with it. Especially as they're far better at repairing body work than fixing mechanical problems.

Anything I can do to fix?

Cheers,

Digerati

jgmilberg

The sensor or the sensor harness could have gotten damaged in the accident and it needs to be replaced or repaired. The body shop might not have put the sensor back where it goes, out in front of the radiator, and it is reading under hood temp which explains the reading going up every few minutes in traffic. There is little or nothing you can do to fix it, unless you want to see if it is in the correct location, and maybe move it there if you can find where it is now. Beyond that I would take it in. If you raise a big enough stink about having to bring it back you should be able to get a dealer demo/loaner car until it is done.

q45man

Always read warmer than the real [as measured in the shade] air temp. Since the exhaust heat from cars and warmer roads radiate upwards. Most systems are within 5 degrees except in bumper to bumper traffic when 10F is not unusual.
A change from usual does mean the sensor was moved.

digerati

Spent some time underneath the front end of the CLK today and found the temperature sensor dangling on the end of its wire. The manual said that the sensor is mounted in the front bumper area, and after a while I found an empty hole next to the driver's side foglamp into which the sensor fitted.

So, success! And without a visit to the body shop... :-)

Thanks for the suggestions -- helped me find the sensor.

Cheers,

Digerati