E46 outdoor temp sensor

[sancroce]

Hello:
My wife ripped the front left splash shield (the one that has the Temp sensor) and the dashboard started to show -40F plus the blinker will run fast (sometimes)
So, I bought a new sensor, attach it to the cables (both ways) and turn on the car. Temp keep showing -40F. So I went under to take a closer look and I found a blue cable that is peel but connected to nothing. Just hanging in there like the pic shows.

Anybody know what is that cable for? has anything to do with the problem.

IMG_3411.jpg

[charter21p5]

See if you can find the ETM for your car. It should tell you what that connects to that wire. You definitely found the source of the issue.

[charter21p5]

So looking at the etm the blue wire with red stripe connects to the temp sensor.

Wire color code abbreviations are listed here:https://www.bimmerforums.com/forum/s...for-schematics

There should be two blue wires for the temp sensor circuit one with a red stripe and one with a brown stripe.

[Mless5]

For some reason, you need to wait a day or 2 before it starts to read actual temp (granted everything is connected properly).

[Ateyourv8]

Follow that harness of the ripped wire to where it starts to shrink wrap and there you should find the other end of that wire. Reconnect and you should be good there.

As far as the ambient temp sensor reading -40, ive heard for some people it reads right away and for some it takes a while. I would double check the wires for the temp sensor and make sure they arent stretched or ripped internally farther down the harness. If you have a multi meter: check for continuity in the wires. If all checks out, leave it and see if starts working after a bit.

[MarcoZandrini]

The ambient air temperature sensor is nothing more than a thermistor. A thermistor is a resistor that changes resistance as it’s temperature changes. All temperature sensors in the car, including the engine temperature sensors, are thermistors. There is no waiting time. There is no calibration needed. It’s simple electronix.