OBC Ambient air temp sensor location????

[tubbs76]

Hi all, i want to replace the air temp sensor as my obc is reading -35C. After reading through the site, looking at google, etc.. seems it is located at the front of the car, driver or passanger side and norm. Dependant on write up, located in break duct, under front spoiler, near fog lights etc. Just one problem, mine isnt in any of those locations and it is starting to crack me now.I csant eben seem to find sanything that remotely looks like it. Ive searched on line to make sure my car has one and it has according to obc and bmw schematics based on vin number. Anyone have any clues as to where it may be hiding? All help appreciated on this one guys as it is now doing my head in
Tubbs76

[e36msp]

Drivers side brake duct. The is an air duct that directs air towards the brakes for cooling. Its located in there.

[tubbs76]

Hi Mate,

Had a look and nothing there. Ive checked both sides. No loose wiring and there isnt even a hole in the duct where the sensor would sit. Ive also looked near fog lights both sides and underneath wheel arches both sides and found zip.. Im trying to use logical thinking about this and i figure it has to be where there is air flow?? Ive looked at front grills, bottom grill on front spoiler. The only other place I can think it may be is somewhere under lights which would be wierd. Any other suggestions??

[shogun]

is your car in Australia EURO version? Right hand drive?
On the EURO version it is located besides the left (from viewpoint sitting inside the car) foglight respectively if there are no foglights besides that cover in the air duct, behind the fog light area, left hand side (aka driver's side in North America)
here is a pic
http://www.bmwe36blog.com/2007/07/04...or-in-bmw-e36/

[flyfishvt]

The senosr is bright yellow so if it was there you would have found it by now. The wires for the sensor come from the same harness that has the headlight and parking light wires. I suggest you trace all the wires from those two harness bundles (driver then passenger side) and you will find the wires that go to it. Like a lot of e36s the sensor has most likely been ripped off the harness.

The wires have to be there. You just have to make your way down through the whole maze of wires until you find it. One other thing is if your car is equipped with the Winter Package you will have an additional sensor that turns on the heaters for the washer jets. This sensor is round and silver. It will have two green wires going to it. It will be located on the opposite side from the temp sensor. Its called a Thermo Switch. An easy way to tell if yoiu have the winter package is to look at the bundle that goes up the hood strut to the washer jets. If you only see a tube then you don't have it. If you see a small wire bundle next to the tube then you have the winter package and you will/should have the thermoswitch.

Both the thermoswitch and temp sensor are well known for getting ripped off the harness over time so if you have the winter package dont confuse the wires for the thermoswitch with the wires for the temp sensor.

[MParallel]

RHD or LHD doesn't matter. It's in the LEFT brakeduct.

Some people say "drivers side" brakeduct. Now that does make it matter if it's a LHD or RHD car.

Just say left brakeduct and it's always good.

[tubbs76]

Hi all,

Thanks for the help, much appreciated. Unfort due to time diff couldnt respond until now. I ordered another sensor (Yellow & Black) which arrived yesterday. It may well have possibly been ripped off all together. It def isnt in the brake ducts or near the fog lights, cant even see a wire with a female attachment it would go in so me thinks I will have to start with the wires both sides of light cluster and work my way down from there. Hopefully ill find a loose wire somewhere so I can repair it. Is it true that the ambient air temp sensor also has some type of control over the ac unit (regulates cold air/ blower / etc or something along those lines???) Ive spoken with a few people, all with varied responses.

Thanks again all.

[shogun]

I know it from my E32, the ambient air temp sensor is only for the OBC to give you the 'black ice' warning at plus 3 degree C and to rear the actual ambient air temp on the OBC.
But the temp sensor for the heater and aircon is located next to the blower motor as shown here
http://bmwe32.masscom.net/johan/ihka/temp_sensors_3.jpg

should be similar on the E36

all temp sensors shown on E32 and E34 here, just to give you an idea
http://bmwe32.masscom.net/johan/ihka/ihka.html

[flyfishvt]

There is an option for Auto Climate Control. I don't know much about it. Its called AUC or something like that. The only function Ive seen is when it automatically turns the climate control onto recirculate to block noxious fumes from outside the car.

As far as I can tell this was only offered in non-US cars. There may be other functions that I'm not aware of and these functions may be partially controlled by the temps sensor you are replacing.

Other than the possibility of that Auto Climate Control the temp sensor is only for the OBC.

Euro Spec guys?

[JDStrickland]

Hi Mate,

Had a look and nothing there. Ive checked both sides. No loose wiring and there isnt even a hole in the duct where the sensor would sit. Ive also looked near fog lights both sides and underneath wheel arches both sides and found zip.. Im trying to use logical thinking about this and i figure it has to be where there is air flow?? Ive looked at front grills, bottom grill on front spoiler. The only other place I can think it may be is somewhere under lights which would be wierd. Any other suggestions??

The air temp probe is yellow, and it lives inside the duct work that directs air onto the left front brake. It is there. It is nowhere else. If it is not there, then it got ripped out, or cut off.

[MParallel]

There is an option for Auto Climate Control. I don't know much about it. Its called AUC or something like that. The only function Ive seen is when it automatically turns the climate control onto recirculate to block noxious fumes from outside the car.

As far as I can tell this was only offered in non-US cars. There may be other functions that I'm not aware of and these functions may be partially controlled by the temps sensor you are replacing.

Other than the possibility of that Auto Climate Control the temp sensor is only for the OBC.

Euro Spec guys?

Now you're confusing things.

Auto climate control could be abbreviated as ACC. This however does not have anything to do with the optional AUC function, on the ACC (an option on an option).

Well apart from that, the temperature has nothing to do with the AUC function. AUC, aka auto recirc has a separate sensor, called *drumroll* AUC sensor. This detect polution in the air and if it goes over a threshold, closed the fresh air flap.

The brakeduct temp sensor is SOLELY for the OBC temp indication.

[tubbs76]

Hi All,

Thanks for the help again, I pulled the left brake duct out and there is a little hole in it so im assuming this is where the air temp sensor should be. Ive put in in and it clips in nicely. It looks like the loom with the female plug it connects into has been ripped out or tucked away somewhere in the engine compartment as I cant see it anywhere. Im going to jack the car up at some point today and get underneath and see if i can find it anywhere though I have a feeling the whole loom has been ripped off as i cant seem to find any wiring anywhere that is loose leading down to were the air temp sensor since. If this loom originates from where the light cluster loom is somewhere, does anyone know which one it is as it looks like ill have to buy a a loom with female connector and graft it in. SO next question....Anyine know where to graft it in??

Thanks again in advance all. If helps, mine is a Euro spec (UK) that was a private import into AUS.

[flyfishvt]

The wire loom will be wrapped in tape like the rest of them so you really won't be able to tell one from another. There should be about 4 smaller looms comming out of the main harness. Just start at that junction and follow each on to its end. One of them will be the one you're looking for. Between the corner light loom and the head light looms and the fog light loom and the horn loom there's a lot of wires coiled up down there. I just replaced mine and Ive done it on two other cars. The only way to find it is to do what I just said. You don't need to jack the car up. Everything you need is accessable from the top.

[tubbs76]

Thanks Fly,

I will have to do this Sunday at some point. If I find the wires, I assume ill need to buy the female connector and some wires from the wrecker as i cant see a female plug anywhere to put the sensor into. By chance do you remember roughly where it was on the loom you did? may help me save some time
Cheers

[flyfishvt]

If you are replacing it with a OEM sensor then you need a yellow female connector. Ive been all over the harness of a few junkers and there are only two yellow connectors used. One is for the temp sensor and the other is in the two front doors on the door handle assembly. You should have figured out by now that the colors need to be matched for the two pieces to fit together correctly.

Just find a yellow connector and cut off enough wire to make it easy to splice it on.

As for where its all located...that's been covered several times. The main wire loom bundle comes down to the front of the car to the headlight area. That is where is splits to all the other smaller bundles for the individual items in that area. That's where you start. Trace the headlight wires back to where is splits off the bundle and start there.

[tubbs76]

Will do, Will purchase female connector with some wiring attached and then begin the search..

Thanks again guys

[tubbs76]

Ok all, back. Went to the wreckers this Morning and got the female connector with the 2 wires still intact, (approx 20cm) I saw them cut it from the loom. Had a good look as the bar was off the donour vechicle. So i went home and started exploring each run off in the loom going to various other components (fog lights, light cluster, radiator temp sensor, etc...) only one problem.....
none of the wires match the colour of the wires on the part i have. Not even in the main loom they all run off.
So question is, does anyone know if bmw changed the wire colours.?
To conform, the loom the gave me (saw cut off) from car has the air temp sensor still attached and it matches the part # of the new one i purchased end of last week.
The colour of the 2 wires in the female plug are orange and muddy grey green (stripped) and the other looks like a muddy grey green if that makes sense
As always, all help appreciated

[flyfishvt]

In that case the only thing I can think of is the two wires you're looking for got cut off all the way back at the main loom. Follow the headlight wires back to where they branch off and peel back some of the wrapping. See if the cut end of your wires are in there.

[tubbs76]

me thinks me will have to. Ive looked in the individual looms to no luck, Im just going to have to do them all again including main one by one in full to see if there is a cut wire in therer somewhere.

[JDStrickland]

You should not have to look very far. There should be signs of wires coming out of the existing loom very near the location of the temp probe.

Nobody in their right mind would unwrap the wire harness to cut wires off, then re-wrap the harness to hide their handiwork.

[tubbs76]

Hi JD, you would think not, but I can suusre you there are no loose wires anywhere. It has never worked since ive owned the car, 3 yrs now, and is one of ythose things ive always been meaning to get around to do. the search continues

[Joker97M3]

Sorry to dredge up an old thread, but my ambient air temp sensor is also missing, and the wires are dangling right by the drivers side brake duct.
Problem is, as mentioned above, the female part of the connector is no where to be seen. I've looked and I can't seem to find the female part of the connector for sale anywhere.
Is it a junk yard part only? Or is it available on-line from a vendor?

Any help is much appreciated.

[Joker97M3]

TTT for anyone who might know where to buy the female part of the temp sensor connector.

[flyfishvt]

you can pick one up at the dealer. I don't have the part number. You will probably have to buy the wires that go with it separately. All those parts are available at the dealer. That is the only place I know of except a junk yard.

OR you can look on ebay for an after market temp sensor that has its own pigtail and just splice it onto the ends of the wires like i did on my other car.

[Joker97M3]

you can pick one up at the dealer. I don't have the part number. You will probably have to buy the wires that go with it separately. All those parts are available at the dealer. That is the only place I know of except a junk yard.

OR you can look on ebay for an after market temp sensor that has its own pigtail and just splice it onto the ends of the wires like i did on my other car.

Cool. Thanks. I'll check both of those out.