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OBC temperature

3963 Views 7 Replies 4 Participants Last post by  toddster
My 7 button OBC is displaying a temerature of -35°F and -37.0°C. What is causing this error?
Also the LCD display in this area is weak and some lines are partially displayed when they are and are not to be lit up.
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Bad sensor or connection. When the brake duct falls out the sensor could be damaged from being dragged on the road. I'm not sure how to test it to see of its working right, someone else might know. Look for any damaged wires while you're at it.

Oh and only the 18-button computer is called the OBC (on board computer). The 7-button and 11-button models are called a MID (multi info display). :thumbup:
The temp sensor circuit is open and the OBC is displaying the lowest possible reading because of that. As Engel stated check your driver side brake duct to see if it's still there and if it's gone see if the sensor is still there. When you have a sensor in place and the connections are good it should read close to the outside air temperature. To check the accuracy, mix a slush of water and ice in a styrofoam cup and immerse the tip of the temp sensor in it. The OBC display should read 32-33 degrees if its set for Fahrenheit, or 0 if the OBC is set for Celcius.
Bad sensor or connection. When the brake duct falls out the sensor could be damaged from being dragged on the road. I'm not sure how to test it to see of its working right, someone else might know. Look for any damaged wires while you're at it.

Oh and only the 18-button computer is called the OBC (on board computer). The 7-button and 11-button models are called a MID (multi info display). :thumbup:
The temp sensor circuit is open and the OBC is displaying the lowest possible reading because of that. As Engel stated check your driver side brake duct to see if it's still there and if it's gone see if the sensor is still there. When you have a sensor in place and the connections are good it should read close to the outside air temperature. To check the accuracy, mix a slush of water and ice in a styrofoam cup and immerse the tip of the temp sensor in it. The OBC display should read 32-33 degrees if its set for Fahrenheit, or 0 if the OBC is set for Celcius.
(Lower resistance means lower temperature. like how superconductors work.)

Ah, that is right, I forgot it was called the MID.
Anyways, I no longer have the brake duct in my left side bumper. Not sure if the car lost it when I hit a concrete median or when the previous owner had that corner sideswiped by pulling out too far into a road.
So, what does this sensor look like, the wires to it, and is it on a '92 318i? I have read things in these forums that make me believe it wouldn't have this being too early a model. Oh, and a place to buy.
Found it missing on my car. Found two wires cut in the Left Front corner of my car near the two horns.
... now, how to replace ...
Buy a new one. They're around $25. You also have to buy the socket that actually attaches to the wires, because the probe just has a plug on the end. Sometimes they come as a kit. I found a hole in the radiator shroud that it would plug into, in a relatively secure fashion. I suppose that you could roll your own from a similar thermocouple, but weather-proofing and calibrating it could me more hassle than it's worth.
where to purchase either?
I got a set from Bavarian Autosport. They're not the only ones. Google part # 65 81 1 383 204
For the plug kit, the BA # is 61131378419KIT
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