1 engine, 3 temp sensors?
 

It looks like my car has 3 coolant temp sensors. I need to know what each of them do, so that I can check and replace them if they are bad. Below is a picture of my car's 2.3 8v engine's front side(1st pic - thermostat housing, 2nd pic - engine fan)
I have numbered parts that look like sensor. The sensor #1 is more complex. It has 4 wires coming to it. The others just have 1 wire.

Thanks

here is a third temp sensor

i think the 4 pin sensor is linked to the fuel injection system and
ignition system-that is what it is on my 1993-190e-1.8 litre uk spec 1993 car.

sorry do not know wht the others are.

I'm not familiar with that engine...
 

But I do remember you have a 230E? (Euro?)

If that's an M103 engine, the #1 picture is the 4 pin temp sensor which the previous poster accurately identified as involving the Bosch fuel injection system. The sensor feeds the system info, and your fuel injection system reacts accordingly.

You should also have a two pole, and a single pole temp sensor. The two pole is the ACC emergency cutoff sensor, that kicks in the high aux fans at 105deg?, and shuts off the AC compressor at 115deg to prevent damage.

The single pole temp sensor relays the temp to your dash, and nothing else.

G'luck :p