W213 Temp Sensor Wiring

[ianro]

Dear all
can anyone tell me the colour of the wiring of the engine bay temp sensor wiring please. The sensor is 2 wire grey and white and the main loom is yellow and brown but I don't know which goes to which?
Appreciated.

 

[Supernoodle]

Not sure what the engine bay temp sensor is, but 2 wire temp sensors are effectively just variable resistors. They don't have have a polarity

 

[ianro]

When I check the sensor it doesn't read as an open circuit but reads something like 2.16, this is the replacement sensor I fitted thinking the 1st had failed.

 

[Uky]

I do not know if what I write is applicable to 213/238 but:

Some bean counter at Mercedes thaught that since temperature sensors wires do not
carry any specific current so there is no need for thicker wires.

As a result to this decision, what have happens is that when bending a cable harness
during installation, that amongst all other cables, the thinner sensor wires break inside
the harness.

Also given the fact that Z-joints (several cables connected in one single point inside
the harness in order to save cable length) and that there have been cases where these
joints break.

Any strange error code(s) or in this case possible strange climate or engine behavior
should be adressed with the above in mind.

 

[ianro]

As above, when I check the impedance I expected OL, open circuit yet gives me a reading?

 

[Supernoodle]

Why do you expect it to read as OL? And 2.16 what? Ohm? kOhm? MOhm? A few more words needed.