Outside Temperature Reading Incorrect!!!

[X88RED]

Hello!

Just wondering if anyone on here has any more idea on an issue I'm getting with my outside temperature reading. Basically it's constantly showing a lower reading than normal and will sometimes even warn of ice. BMW have already replaced the sensor and the wiring and also reset the entire setup. The whole issue has now been submitted as a case to BMW for further investigation. However I was just wondering if anyone on here may have an idea of what could be causing this? Just so I can put it to BMW and maybe aid in fixing this issue. My car is a 2007 e92 m3.

Thanks in advance!

Redmond

[thekurgan]

Check in your driver's side air intake (lower apron), there is (supposed) the outside air temp probe. Maybe it's been damaged.

[X88RED]

Originally Posted by thekurgan

Check in your driver's side air intake (lower apron), there is (supposed) the outside air temp probe. Maybe it's been damaged.

As far as I'm aware that's already been replaced

[thekurgan]

I guess I was thinking this was a repeat damage. The sensor is simple, unless you've got an ECU issue or the wrong sensor (but I believe all BMW outside temp sensors are the same).

[sinth]

Originally Posted by X88RED

Hello!

Just wondering if anyone on here has any more idea on an issue I'm getting with my outside temperature reading. Basically it's constantly showing a lower reading than normal and will sometimes even warn of ice. BMW have already replaced the sensor and the wiring and also reset the entire setup. The whole issue has now been submitted as a case to BMW for further investigation. However I was just wondering if anyone on here may have an idea of what could be causing this? Just so I can put it to BMW and maybe aid in fixing this issue. My car is a 2007 e92 m3.

Thanks in advance!

Redmond

Ive got exactly the same problem but mine keeps reading over. Possible +20C than it actually is.

Ive changed the sensor and had the loom sorted. Still the same problem

Its going back in

[AlpineV8]

I can usually figure out the temperature while walking to my car. If it's cold, I wear more clothes. If it's hot, I wear less. If it's wet, I carry an umbrella.

[thekurgan]

Originally Posted by AlpineV8

I can usually figure out the temperature while walking to my car. If it's cold, I wear more clothes. If it's hot, I wear less. If it's wet, I carry an umbrella.

There's one in every forum.

[Beemdog]

Originally Posted by thekurgan

There's one in every forum.

In some forums a whole gang of jokers is the norm... I appreciate the humor, also appreciate having a temp gauge that is somewhat accurate. There are certainly a multitude of widgets to go wrong on these cars (and most all cars today). I can picture these 20-year-old M cars running around with a list of things as long as my arm that no longer work correctly.

Warranties will only be extended so long...

[AlpineV8]

Originally Posted by thekurgan

There's one in every forum.

I'm pretty sure there's two. I'm waiting for the other to chime in any minute...



But seriously.. if the brake pedal didn't stop your car I would say you've got a problem but I've never known any vehicles temp reading to match that of anything else like say, what the cell phone weather says etc. etc.

[thekurgan]

Originally Posted by AlpineV8

I'm pretty sure there's two. I'm waiting for the other to chime in any minute...



But seriously.. if the brake pedal didn't stop your car I would say you've got a problem but I've never known any vehicles temp reading to match that of anything else like say, what the cell phone weather says etc. etc.

It's true, the damn thing is too close to the ground as well, where temperatures are usually higher. This probe really only affects the auto a/c settings.

[X88RED]

Originally Posted by sinth

Ive got exactly the same problem but mine keeps reading over. Possible +20C than it actually is.

Ive changed the sensor and had the loom sorted. Still the same problem

Its going back in

Let me know the outcome if you can. Everything seems to be pointing the ECU?

[X88RED]

So after BMW changing the sensor, inspecting the wiring and telling me they think they have fixed it due to a loose connection. I have just got a temperature reading of -40c showed up for about 30 seconds then returned to normal though. Any ideas?

[Beemdog]

Originally Posted by X88RED

So after BMW changing the sensor, inspecting the wiring and telling me they think they have fixed it due to a loose connection. I have just got a temperature reading of -40c showed up for about 30 seconds then returned to normal though. Any ideas?

It might be interesting to see what it reads with the sensor unplugged. If it is working fine, then you unplug the sensor and get -40C, then you can bet there is an intermittent open somewhere in the wiring.

[X88RED]

Still having temperature sensor problems - the car keeps warning me of ice and it seems the temperture will change every minute or two

[X88RED]

Just wanted to let everyone know, this issue has now been corrected and it was a faulty instrument cluster!

[Jacooobs`n]

Sorry for bumping an old thread but got the same issue. Mine started a week ago reading 10-15 deg Celcius more than the actual ambient temp is, and sometimes rising while driving. At the same time I occasionally get some misfiring, especially when driving in que when the cold-start fan start making the deeper exhaust sound.
Any advice?
BMW tech will look at my car in 10 days but if he could get some ideas that would save me some hours troubbleshooting.

Thanks in advance

[LVI]

if your wiring is fine (i.e. not pinched or damaged), and the sensor is not damaged and correctly placed in the lower brake duct, then your issue may be similar to what the OP posted - a faulty instrument cluster.

The DME uses the ambient temp sensor to adjust the fuel mixture on this car, so your misfiring could or could not be related. I can tell you that i drove for several hundred miles with pinched ambient temp sensor wire (sensor indicating -40 deg the whole time) and the car ran fine, without any misfires, although the SES/check engine light came on right away.

[Slizza786]

Originally Posted by X88RED

Just wanted to let everyone know, this issue has now been corrected and it was a faulty instrument cluster!

Sorry to bring up an old thread but i am having the same issue. One day randomly my cluster completely stopped working. 2 weeks later plugging it back into the car it started working but now constantly shows -40C. I changed the outside temp sensor but still the same problem. After reading your thread, im very sure i am having the same issue with it being due to a faulty instrument cluster. Could you tell me how you resolved it please?

Also, if the cluster is faulty but the wiring loom and temp sensor are actually fine, will the cars A/C unit and efficiency still be fine or will the car actually think its -40C based on the cluster?