wrong outside temp on display

[curlywurly71]

My main display keeps giving me the wrong temperature reading, like on a bright sunny day it says -6 , any ideas why?

Thanks
             curly

[saskak]

My main display keeps giving me the wrong temperature reading, like on a bright sunny day it says -6 , any ideas why?

Thanks
             curly

Has it always been wrong or did it just happen and is it always the same temp displayed (-6)? Might be a faulty sensor. On the M59 they are in the driver's mirror, not too sure on the B9, but I suspect it will be the same position, others might advise otherwise. Pretty cheap sensor and not too difficult to test/replace.

[curlywurly71]

My main display keeps giving me the wrong temperature reading, like on a bright sunny day it says -6 , any ideas why?

Thanks
             curly

Has it always been wrong or did it just happen and is it always the same temp displayed (-6)? Might be a faulty sensor. On the M59 they are in the driver's mirror, not too sure on the B9, but I suspect it will be the same position, others might advise otherwise. Pretty cheap sensor and not too difficult to test/replace.

It happens on and off, but only in the last month or so and can suddenly go from 15 to -6 in a dip in the road and for no apparent reason.

[saskak]

It could be a faulty connection in the door loom and/or the actual sensor. If I am correct in assuming that the position of the ext temp sensor is in the driver's mirror, then the connection pins are probably described in this thread: https://www.berlingoforum.com/thread-4053-page-2.html (bear in mind this is for the M59).

Can someone correct me if I am wrong to assume that the ext temp sensor in the B9 is in the driver's mirror?

You can probably measure the resistance in the ext. temp sensor from the door loom's pins and see if it fluctuates. The resistance should decrease as the external temperature increases. It is probably a linear function of the temperature, measure, plot and see if it behaves accurately. Then you would know if it is the sensor itself or somewhere past the door loom.

[deejay_xb]

the temp sensor is in the mirror, passenger side for LHD or driver side for RHD.

[saskak]

the temp sensor is in the mirror, passenger side for LHD or driver side for RHD.

Thank you deejay. That's what I thought, there would be minimal differences between the successive model versions. Basically the driver's mirror. The same with the M59, the driver's mirror is the one without the motor to operate the mirror, hence the missing motor connection pins can be used for the ext temp sensor.

If the mirror in the B9 is motorised, then it is different pins for the ext temp sensor.