Mercedes temp sensors

So, my dashboard says the outside temperature is 185 degrees.... hmm..

Looks like the ambient temperature sensor is broke, gone, etc.

(note: there are a LOT of temperature sensors, so you want to be sure of which one you want)

Replace ambient temp sensor

First to find it, other cars have it somewhere on the lower front. Sure enough, looking at the lower grill, you see a hole with a little probe sticking out.

  • So first remove the six 8mm bolts that hold the front under cover on.
  • Now you can reach inside and unclip most of the grill. There are 2 vertical metal bars and there are 2 clips on each one on the grill, spread them out carefully and push the grill out a bit.
  • Then there are 4 more clips on the bottom edge away from the 4 you just undid, push them up gently, and the bottom will move out some more.
  • Now for the two tricky ones in the upper right corners of the corners of the grill.
  • Be very careful how you release these! They are released from the front outside of the car.
  • Get a small flat blade screwdriver and look into the square hole with a bright light, you can see a small flat opening just inside the square hole, you want to insert the screwdriver into it (it is not deep) as vertical as you can get. Then gently raise the end of the screwdriver, it does not take much. Pull out on the grill a bit while doing this.


 show picture of back of cover

show picture of bottom panel


The part number was 000 542 84 18, but also replaced by 007 542 13 18, the latter number is easier to find, I bought a Dorman one for $13 on amazon.

OK, replaced it and still 185 degrees.

Need to check wires and connectors.


here's a link about the ambient temp sensor:


video of location of modules:


Interior temp sensors

One in the overhead console (where map lights are) and one in the center panel (kind of where the switches are)

in car sensor n22b1 (behind AAC panel N22)

ambient sensor in overhead console n70b1 (in overhead console N70) data send to N22

both have little fans to draw air over the sensors, the in dash one has air from the ventilation blower

these sensors are each used up to 50% and then compared to the ambient temp sensor (front grill) B14





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