[nfiftyfourgasm]

So on my 2007 e92 335i my outside temp sensor wires got ripped off at the passenger wheel well area after running over a pothole. I soldered the wires back together and got a new sensor and pigtail connector just in case it messed up the pins. Still same 2F9A code and reading -40 degrees. I checked for power going to the connector from where the wires broke and I had 4.1 volts when I tested from the power wire to the sensor and ground on the jump point nut. But when I tested for power from the power wire and ground wire going to the sensor I had nothing. Would anybody be able to help me find a diagram of where that ground leads to so I can test for continuity to find my open ground?

[gbalthrop]

Attached are ISTA ScreenPrints for 3/2007 build 335i Ambient Temp Sensor circuit, Connector Locations, & Connector Views.
The Ground is NOT Chassis Ground, but rather a connection to the JBE Module, Blue X14271 Connector, with a "passthrough"
to the KOMBI/Instrument Cluster. So there SHOULD be continuity between X770/1 & X14271/19, via Blue/Brown wire.
If any questions on HOW to test, please advise. Please let us know what you find, & attach photos, & your VIN-7.
George

[nfiftyfourgasm]

Great timing! I got my hands on these same diagrams about 30 mins ago from a local shop helping me out and I tested for continuity to the sensor from pin 4 and 19 on connector X14271 and both were perfectly fine. I also tested for voltage again at the sensor connector (pins 1 and 2) to chassis ground because I suspected that the blue and brown wasn’t a ground but rather like what you said in it being a pass through from the JBE and sure enough I had 4.1 volts through both pins. So since I have voltage at both blue/red and blue/brown I might just be overthinking it so I’m currently letting my car sit with battery unplugged in an attempt to let it reset itself and maybe drive around for a bit if I’m still reading -40 degrees. I’ll keep you updated and I very much appreciate the help!

[gbalthrop]

Originally Posted by nfiftyfourgasm

... I tested for continuity to the sensor from pin 4 and 19 on connector X14271 and both were perfectly fine. I also tested for voltage again at the sensor connector (pins 1 and 2) to chassis ground because I suspected that the blue and brown wasn’t a ground but rather like what you said in it being a pass through from the JBE and sure enough I had 4.1 volts through both pins...

If there is contact between the TWO wires, Blue/Brown AT-, & Blue/Red AT+, you would have continuity between X14271 & X770, but SAME Voltage at each socket of X770. If that is what you are seeing, test for continuity between X770/1 & X770/2, with X14271 DISCONNECTED, & if near-zero Ohms, the two wires are contacting each other.
George

[nfiftyfourgasm]

Also for me apparently X14271 is the blue connector on the right side and X14272 is the black connector on the left side for some reason. As for the suspecting the red/blue and blue/brown are contacting each other I did test that earlier today by having X14271 unplugged and checking continuity at pin 1 and 2 at X770, I even checked continuity at pin 4 of X14271 to pin 1 of X770 and vice versa with pin 19 on X14271 to pin 2 on X770, in which all these tests read open on my meter to confirm that the wires aren?t contacting each other. The picture I attached is testing pin 19 of X14271 to pin 1 on X770 which shows perfect continuity to confirm the blue/brown is perfectly fine. With KOEO both pins at X770 read 4.1 volts, so I?m thinking so far that the wiring is fine and I just need to let the -40 degree reading on my cluster reset itself by driving around for a bit. I?ll keep you updated and thank you again!!!

[nfiftyfourgasm]

Just a quick update, after letting my car sit with battery unplugged and driving it around to attempt to let my outside temp sensor reading reset itself it’s still the same. Continuity is perfect from both pins on my sensor connector up to the connector on the JBE but I am still reading 4.2 volts at both pins on my sensor connector when tested to chassis ground. Doing some research on my own I read that one of the pins on the connector (blue/brown wire) is supposed to be a monitored ground and should not carry voltage with the sensor unplugged. What should I check to see why the monitored ground is receiving the same voltage as my reference voltage?

[nfiftyfourgasm]

Adding onto my last statement I did also check to make sure my blue/red and blue/brown wires weren’t shorted together between the JBE connector and my sensor connector with multiple methods which I stated earlier in this thread so I’m still wondering why would my monitored ground wire be reading the same voltage as my reference voltage wire? Issue with JBE maybe? I did get a new dme and cas module but I had a shop clone my previous dme and cas to my car and I have no other issues with the car besides this one so I don’t think that has anything to do with it, but I could be wrong.

[nfiftyfourgasm]

I added a picture which includes my vin and the 2f9a code I’m receiving if it’ll help anyone to help me figure out a way to diagnose this issue. I’d greatly appreciate anybody’s help or advice!

[Sgop335]

cant get a new or used one?

[nfiftyfourgasm]

Already bought 2 new sensor mate

[gbalthrop]

Originally Posted by nfiftyfourgasm

I added a picture which includes my vin and the 2f9a code I’m receiving if it’ll help anyone to help me figure out a way to diagnose this issue. I’d greatly appreciate anybody’s help or advice!

I assume the Ambient Temp display on the Instrument Cluster always reads -40 when the ignition is ON? It is NOT clear to me what electronics within the JBE may be involved (if any), or whether the JBE only serves to connect the Blue/Red wires between X14271 & X14272, along with the Blue/Brown "AT-" wires between those two connectors. Your tests thus far appear to OMIT any test of the connection supplied by the JBE, OR the Instrument Cluster function & wiring between KOMBI & X14272 (Black Connector).

Your initial post suggests the issue arose AFTER hitting a pothole with resulting damage to the wiring in RF Wheelwell. You gave NO specifics, or photos, such as fender liner came loose, or location of any damage, but the suggestion was that there was visible wiring damage (without identification of wire colors) in RF Wheelwell. So I focused on the wiring between JBE & Ambient Temp Sensor. Subsequently, you appear to have ruled OUT any damage between JBE X14271 & Sensor X770. I would suggest NOW testing JBE X14272 to KOMBI X11175, as well as F58.

ISTA ScreenPrints for the circuit between JBE X14272 & KOMBI (A2a), as well as Power supply via F58 are attached to NEXT Post. These relate to your 12/2006 build 335i. If the JBE is merely a "Passthrough Connector" between X14272 & X14271, the power is supplied by the A2a KOMBI Module, which is powered by fuse F58, which supplies power to BOTH KOMBI (X11175/9) & OBD II Socket, X19527/16. Please let us know what you find.
George

[gbalthrop]

Attached are ISTA ScreenPrints related to prior post.
George

[nfiftyfourgasm]

I added a bunch of images that confirms I have a clear path from the cluster connector to my temp sensor connector. Did the same tests from cluster connector to X14272 to the JBE so I can assure that I have a clear path on both wires. I also tested if the wires were contacting each other from the cluster to the temp sensor connector and I confirmed that they are not. I am wondering why I’m getting the same voltage at my monitor ground as my reference voltage with the sensor plugged in. I tested with 3 different sensors including one from a friends car (same year make and model) that is 100% functional and still got the same reading. Since the sensor is a resistor I’d think that I should be getting less voltage at my monitor ground than my reference voltage. Any advice on what you guys think could be faulty? Thanks!
-Jonathan