I replaced my valve cover and pinched the O2 sensor wire. I replaced the valve cover, smoked checked it for leaks (no leaks), and replaced the bank 1 sensor sensor 1 that got pinched. Since the replacement f the o2 sensor, the cars service engine soon light won't turn off. I can reset the code using the scanner, the light goes away, and drive as far as I want and the light won't come on. The second I turn the car off and back on the lights on and the code is present again. The car drives better than it ever did, the sensor is new, double checked it was the right sensor. What am I missing? Do I need to drive a certain amount of miles to reset it, or is there a fuse that may be blown? There are no misfires or any other codes being read. 2012 BMW 128i
What code is it setting? Can you read the live data from the sensor?
Life's tough. It's tougher when you're stupid. -John Wayne
The code says bank 1 sensor 1,
bank 2 sensor 1,
bank 1 sensor 2,
bank 2 sensor 2
I don't have the exact code numbers until I get home. The scanner I have isn't equipped to read live data from the O2 sensor. There were no codes until I plugged in the new O2 sensor. It's a Bosh sensor, so no wiring or soldering, just plug it in.
The code says
bank 1 sensor 1, p0031
bank 2 sensor 1, p0050
bank 1 sensor 2, p0037
bank 2 sensor 2 p0057
I don't have the exact code numbers until I get home. The scanner I have isn't equipped to read live data from the O2 sensor. There were no codes until I plugged in the new O2 sensor. It's a Bosh wide band A/F sensor , so no wiring or soldering, just plug it in.
I was thinking maybe a fuse, or that the car had to be run a certain amount of mileage for it to relearn, but I'm not sure where the fuse for the o2 sensors are on a 2012 bmw 128i. I looked under the hood in the upper left wiring box (they used to be there in older models) and don't see any fuses.
ugh, p-codes.
in general - all of those codes point toward heater control issues on the oxygen sensor circuits. usually this is due to pinched or damaged wiring - possibly bad ground(s).
a scanner that can read live data would be very beneficial here (which could be used to check for heater and sensor activation/performance/behavior) - as well as some basic circuit checks with a multimeter would likely be the course of action.
this is definitely a new enough car that having the proper scan tool is critical to performing any diagnostics.
just trying to think of easy things - are you 100% certain the replacement sensors are the correct part?
- - - Updated - - -
also, meant to add - i would check fuses (since this is cheap and easy). fuse locations and details should be in the service manual (such as newtis.info) and other sites. if bentley has a manual for this model, it'd be in their publications too.
'95 325iS - auto to manual swap done!
I only replaced 1 sensor (bank 1, sensor 1) because I had pinched the wire when putting the valve cover on. Prior to this there were no codes. I replaced this sensor with Bosh part#17098, it was an exact fit. Once I started the car I then got a code for all 4 sensors, so I really don't think it's the sensors. I can erase the codes, drive with no light on as far as I want, but when I turn the car off and back on I get the codes and the service engine soon light. The car runs great.
as i mentioned - you need to start doing diagnostics then - check fuses, check power/grounds for the o2 sensor circuits. view the o2 sensor data to see what the computer is seeing.
make sure all connections are tight/clean, and correct.
'95 325iS - auto to manual swap done!
no, no need for mileage to pass for reset.
'95 325iS - auto to manual swap done!
i'd only note what i stated before....
also, meant to add - i would check fuses (since this is cheap and easy). fuse locations and details should be in the service manual (such as newtis.info) and other sites. if bentley has a manual for this model, it'd be in their publications too.
as i mentioned - you need to start doing diagnostics then - check fuses, check power/grounds for the o2 sensor circuits. view the o2 sensor data to see what the computer is seeing.
make sure all connections are tight/clean, and correct.
'95 325iS - auto to manual swap done!
Replace fuse # 38, in the Junction Box. 30 amps; green.
https://screenshots.firefox.com/jHI0....prodemand.com
The screenshot will disappear in 14 days
The orange wire feeding all 4 sensors goes to fuse 38.
Last edited by bmwdirtracer; 12-06-2018 at 07:50 PM.
Chris Powell
Racer and Instructor since, well. decades, ok?
Master Auto Tech, owner of German Motors of Aberdeen
BMWCCA 274412
German Motors is hiring ! https://www.bimmerforums.com/forum/s...1#post30831471
I CANT BELIEVE IT!!!! I pulled the glove box, opened the little card, pulled out fuse #38 and the inside circuit is broke as all hell. 100% blown fuse! On my way to auto store now! Let's hope that when I pinched the wire it blew the fuse and that's all that's left! Will keep you updated, you guys have saved me thousands!
UDATE!!!!!!!!!!!! Fuse #38 was the issue! After replacing the fuse all codes disappeared! For the first time in a long time there are no warning lights on the dash, I had to sit and stare at it! I turned the car off and restarted it several times and still no codes or lights. Took the car for a spin and screamed down the highway. This is my wifes car, so shit is finally happy around here! Can't thank you guys enough.
Chris Powell
Racer and Instructor since, well. decades, ok?
Master Auto Tech, owner of German Motors of Aberdeen
BMWCCA 274412
German Motors is hiring ! https://www.bimmerforums.com/forum/s...1#post30831471
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