The splash panel that had the sensor broke and the sensor and plug were pulled off by a snow bank here in the normally snow free Southeast VA. Anyway, I ordered the repair kit and a new plug from BavAuto and hooked it up. I wanted to solder the wires together rather than use the crimps for a better connection. Before it joined them permanently, I twisted them together to make sure it was working. When I did this the temperature still read -40. After some reading, I saw people saying it takes time to register and I went ahead an soldered them hoping it would work. Well, two weeks later I'm still seeing -40 and it's 60 outside and my heat is blowing on the climate control even though that's down to 65. Any ideas where I can go from here? Would it help to measure the voltage on the wires? What should it read? Thanks for any help.
Also, anyone who has used the BavAuto repair kit, how far do you need to push the wire with the plug things on them up into the plug itself? I pushed them in there until they wouldn't come back out and it doesn't seem like it would go farther but I didn't try to force it. I didn't want to break it.
Last edited by BoardEm; 03-11-2010 at 04:41 PM.
Check upline and investigate the extent of the damage. Good luck.
do you have the leads reversed? Not sure if that might cause it but it might.
>'97 528i, 200000 miles, Hella Xenons, 17" Stilauto wheels, Vogtland Drop Springs, Dynomax Race Muffler, Homelink, 540 brake upgrade, 15mm spacers >'65 & '74 MG Midgets BFC OT Lego Club #48 Manual conversion in process!!!
Polarity of the circuit not important.
The temp sensor is simply a resistor working on NTC principle.
Check with a voltmeter to see if you're getting power. I bet the wire is broken internally somewhere in the upline.
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>'97 528i, 200000 miles, Hella Xenons, 17" Stilauto wheels, Vogtland Drop Springs, Dynomax Race Muffler, Homelink, 540 brake upgrade, 15mm spacers >'65 & '74 MG Midgets BFC OT Lego Club #48 Manual conversion in process!!!
Last edited by BoardEm; 03-11-2010 at 10:39 PM.
have you disconnected the neg. battery terminal? I had to do that before mine would work, not really sure why.
hi,
I had the same issue on my 1997 528i and simply connecting it was not enough. You have to short the terminals for the sensor to be "accepted". In other words, connect both the terminals to the sensor, get another small piece of wire and while ignition is in postion 1, short the sensor terminals together. You will see the reading from -40F change to the actual one.
I am not sure if this is the recommended way, but it worked for me.
Last edited by BoardEm; 03-12-2010 at 08:09 AM.
Wait, why would the heat be running because of the outboard temp sensor? AFAIK the only thing that affects is the heated mirrors and the REST function of certain climate control systems (maybe that's an E38 thing though). The internal climate control system has its own temp sensors.
What am I missing?
1991 M5 (in progress)
Restoring an old BMW, God help me.
Netstat is correct - you need to short the terminals to calibrate the sensor. I had to do the same thing. With the car off, bend a piece of wire into a "u" shape, and short across both terminals. After it is in place, turn the key to the "on" position, while still on, remove the wire and plug in the sensor. Check the display, the temp should then be correct. Also, the climate control will not work right if the temperature is reading -40.
When the external temperature sensor "tells" the car it is very cold outside, it will turn on the heat in "anticipation". I had the same thing happen wen I damaged my sensor coming back from O'fest a few years ago. I did not have to do any "resetting" when I replaced the sensor however.
Regards
Chet
'03 530 I Sport / '14 M6 Grand Coupe
Black / Black
The drive is the destination
The ambient temp sensor's data does affect the IHKA panel. It receives the data from the temp sensor by way of the ECU...and when ambient temps are BELOW +41 °F...the AC compressor does NOT operate (which dehumidifies the air and makes it feel cooler).
So if the ambient temp sensor is reading -40 °F ...it can make the HVAC system work hard (if possible at all) to cool the cabin.
Also, the "values" (warmed air vs cooled air) configured to keep the interior temp setting varies depending on if it is -40 °F versus the ambient temp being +60 °F.
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mine took a few days to start working fwiw.
God I hope mine is one of the easy ones to fix, then. My sensor is gone, as is the underpanel that held it in place. Gotta find out how much wire is even left under there.
1991 M5 (in progress)
Restoring an old BMW, God help me.
I bought the kit from Bavauto and had the same issue.
It's been a while, but I think the sensor itself comes as one piece but it is actually two, and you have to take the inserted piece out, and then open it up, in order to get the connector ends of the supplied wires all the way into it.
Carefully examine it and you will see where it comes apart. I almost felt like I was breaking it. The connectors on the ends of the wires end up all the way at the end of the plastic male piece when they are inserted properly, then the male piece goes into the female temp sensor itself.
I then just crimped the wires onto the leads. According to "bavarian otto" the polarity is not important.
Good Luck
Fixed. The female plug Bav Auto provides is three pieces; a gray piece, a green piece, and a white piece. I pulled them all apart and once I too the white piece off the wires simply slipped in. Simple instructions saying to take all the pieces apart would have saved me a lot of time and cussing. Oh well. Thanks for the help.
glad you got it working! we all need to throw a few tallies in the win column with our e39 electrical endeavors
I think I still have the email exchange with bavarian otto in which I made the same suggestion. I understand it's expensive to have something printed and inserted with the part, but put the instructions on your site. They have all sorts of great illustrated jobs in their newsletters, seems like this would be an easy addition. Tearing apart that wheel well cover is a dirty pain in the butt job that you really only want to do once.
When mine goes again (I'm on my third one now) I will take pics and make a DIY link.
[I should add this is the ONLY complaint I have with bavauto. Good prices, nice people, great service, & stuff arrives really quick here in CT]
Last edited by jmedarts; 03-14-2010 at 11:20 AM.
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