» Site Navigation | | » Recent Threads | looove 04-16-2024 01:18 PM 04-16-2024 01:18 PM 0 Replies, 1,517 Views | | | | | | 05-23-2009, 11:13 PM | #1 | Senior Member Join Date: Apr 2009 Location: Atlanta Posts: 159 | Coolant temp sensor...2 of them...which one is which? As the title says. There are 2 coolant temp sensors. One if for the gauge, other for the ECU. Bently manual only shows one, the 318ti BMW wiring diagram only shows one... any idea of the front one is for the gauge or is it the rear? 95 M42 Ti | | | 05-24-2009, 10:48 PM | #2 | Senior Member Join Date: Nov 2006 Location: Land of the Vikings Posts: 2,700 | both are found on the cyl. head not sure which one is the one u need though lol.. try pulling the plug on one and see if the temp in the instrument cluster falls out? __________________ Vin Number decode and Retrofit Pdfs Available Free ! Just PM | | | 05-24-2009, 10:50 PM | #3 | Senior Member Join Date: Apr 2009 Location: Atlanta Posts: 159 | I know which wires are for the gauge....not sure where it's supposed to be plugged. Silly me to think the germans would do something so basic as to have the plug only work on the sensor it was intended to | | | 05-24-2009, 11:24 PM | #4 | Senior Member Join Date: Nov 2006 Location: Land of the Vikings Posts: 2,700 | are the connectors the same on both sensors? __________________ Vin Number decode and Retrofit Pdfs Available Free ! Just PM | | | 05-24-2009, 11:30 PM | #5 | Senior Member Join Date: Apr 2009 Location: Atlanta Posts: 159 | Thats what I'm saying The sensors are different part numbers according to realOEM, the plugs are the same. Never figured this while replacing my harness zee germans would do something like that. | | | 05-25-2009, 09:17 PM | #6 | Senior Member Join Date: Nov 2006 Location: Land of the Vikings Posts: 2,700 | Quote: Originally Posted by cracker red Thats what I'm saying The sensors are different part numbers according to realOEM, the plugs are the same. Never figured this while replacing my harness zee germans would do something like that. | ok, after a quick search - "The one for the gauge is 12621747281 The temp gauge is the one with the black connector and the hard to remove wire clip The dme one thats connected to the engine computer with the blue connector thats easy to remove" "12621747281 the black one and 13621709966 the blue one" i have no idea if the info is correct, as the quotes are from 2 different engine types, and 2 different forums, but the info and part numbers seem to corrolate __________________ Vin Number decode and Retrofit Pdfs Available Free ! Just PM | | | 05-27-2009, 03:55 AM | #7 | Senior Member Join Date: Apr 2009 Location: Atlanta Posts: 159 | Thanks Mallard. I've looked at the OEM wiring diagrams until my eyes bleed, and can't find anywhere on there where it says which sensor is which. There are 2 different numbers for those sensors, but they are different than the part numbers. The front sensor is blue, hard to reach one is black. Seems like I might have them swapped around. Tomorrow morning I'll be installing the front knock sensor, and I'll have to pull the upper plenum to get to the wiring for that. I'll swap them around and see what happens. Stupid fan still runs full blast all times. I've looked at the wiring going to it, seems fine. Turns off only by pulling the high speed relay (and key off too). The high speed relay and low speed relay are connected....so pulling the high one won't let the low one come on if I'm looking at the diagrams correctly. | | | 05-30-2009, 08:17 PM | #8 | Member Join Date: Apr 2009 Location: everett, washington Posts: 37 | outcome to switching these wires? did it fix the running issue | | | 06-03-2009, 04:18 AM | #9 | Senior Member Join Date: Apr 2009 Location: Atlanta Posts: 159 | ECU doesn't seem to care which sensor it runs off of, I didn't notice a difference. I've got the ECU on the front one now, the gauge on the rear. | | | 06-04-2009, 02:21 PM | #10 | Senior Member Join Date: Jan 2006 Location: Cincinnati Posts: 890 | Quote: Originally Posted by cracker red ECU doesn't seem to care which sensor it runs off of, I didn't notice a difference. I've got the ECU on the front one now, the gauge on the rear. | Not certain, but I am pretty sure its the other way. Can someone unplug their temp sensor near the front on the head and see if they loose their gauge? Pretty sure they will. __________________ SOLD!!! 1999 332ti //M Sport Titanium Silver M3 S52 3.2 I-6 Engine, M3 Clutch w/ ti Getrag Trans, Z3 3.15 LSD medium case diff and half shafts, OEM Hatch Spoiler, Eurosport HP Underdrive Pulleys, FDM, 17" DS1 rims, M3 Front Struts & Springs, M3 Instrument Cluster, 3-spoke //M steering wheel with tri-color stitching, SSK, CCFL Angels in Depo projectors with 5k HIDs | | | 06-04-2009, 05:24 PM | #11 | Senior Member Join Date: Apr 2009 Location: Atlanta Posts: 159 | Also, see if the front sensor has the blue or black body (front sensor in my car has the blue body) If I have them backwards, it's possible it's causing my gauge to read hot when it really isn't.... | | | 06-04-2009, 10:34 PM | #12 | Member Join Date: Apr 2009 Location: everett, washington Posts: 37 | from what was stated before the blue body sensor goes to the ecu i believe. i did a test with the ignition on and i plugged the gauge into one of them and it had a slight temp reading at dead cold so i knew that was not the right sensor for the gauge. i plugged in the other sensor and it sat at dead bottom as it should since the block is completely cold. and it works great. | | | 06-05-2009, 12:11 AM | #13 | Senior Member Join Date: Apr 2009 Location: Atlanta Posts: 159 | and where was the blue sensor in relation to the black one? | | | 06-05-2009, 12:14 AM | #14 | Member Join Date: Apr 2009 Location: everett, washington Posts: 37 | my blue sensor was in th front black on in the middle/back | | | 06-05-2009, 12:17 AM | #15 | Senior Member Join Date: Apr 2009 Location: Atlanta Posts: 159 | OK cool Blue sensor in front, DME reads off that one Black sensor in middle or back, gauge reads off that one. This is how mine is setup. I work the mid tonight, but I'll swap out with a new water pump tomorrow when I get done. Hopefully that will fix my issue. | | | | Currently Active Users Viewing This Thread: 1 (0 members and 1 guests) | | Posting Rules | You may not post new threads You may not post replies You may not post attachments You may not edit your posts HTML code is Off | | | |