[bmwe90320i-N46]

Hi,

Very stuck here! I have a new catalytic converter and have 4 new oxygen sensors. No engine light now.

HOWEVER the car is starting rough and shuddering. When I connect my OBD2 Tool it's telling me that O2B1S2 (V) = 0.000 all the time, regardless of the car being on, off, accelerating, decelerating, driving or idle.

I have connected a multimeter across the two signal wires going into the ECM, and have used a test light to bridge the signal pins (not power pins) on the harness side connector. I would imagine this means the wiring in between the ECM and harness side connector is fine?
Have I got this right?

If not I assume there must be an internal problem in the ECU. Because I connected the multimeter to the signal wires near the ECU it gave a reading, meaning the ECU wires are connected inside.
For some reason the computer isn't reading the voltage?


Here's the weird bit:
Even when there isn't a sensor plugged into the other sensor 2, when the car is running it reads V = 0.440 always.


Is this a tuning problem?
Is this a wiring problem?
Is this an internal ECU problem?


Please help!

[gT-BMW]

Originally Posted by bmwe90320i-N46

Hi,

Very stuck here! I have a new catalytic converter and have 4 new oxygen sensors. No engine light now.

HOWEVER the car is starting rough and shuddering. When I connect my OBD2 Tool it's telling me that O2B1S2 (V) = 0.000 all the time, regardless of the car being on, off, accelerating, decelerating, driving or idle.

I have connected a multimeter across the two signal wires going into the ECM, and have used a test light to bridge the signal pins (not power pins) on the harness side connector. I would imagine this means the wiring in between the ECM and harness side connector is fine?
Have I got this right?

If not I assume there must be an internal problem in the ECU. Because I connected the multimeter to the signal wires near the ECU it gave a reading, meaning the ECU wires are connected inside.
For some reason the computer isn't reading the voltage?


Here's the weird bit:
Even when there isn't a sensor plugged into the other sensor 2, when the car is running it reads V = 0.440 always.


Is this a tuning problem?
Is this a wiring problem?
Is this an internal ECU problem?


Please help!

I had a similar issue too a few months ago when i installed my AA headers. lumpy idle hesitation part throttle..
I had codes for 02 sensor and just like you it was reading 0. I think its because the pcm goes into a default setting

i solved the issue by using INPA by resetting the codes and adaptions, i was then able to read the 02 sensor V in INPA. The idle was still lumpy but it went away afterawhile. hope your situation is as easy to solve as it was for me. good luck.

[bmwe90320i-N46]

UPDATE:

I tested the ECU wires (black and yellow) on the harness connector pins on both downstream O2 sensors.

The working O2 sensor gave a reading of 0.060 v
The not working sensor gave a reading of 0.000 v.


I have noticed the car starts rough EVERY SECOND TIME. I've consistantly tested this, and it starts perfectly if you start the car, turn it off and start it again.
If you start it again, it rough starts. Turn off and on and it starts fine.


Is this due to the non functioning downstream sensor?

[bmwe90320i-N46]

Originally Posted by gT-BMW

I had a similar issue too a few months ago when i installed my AA headers. lumpy idle hesitation part throttle..
I had codes for 02 sensor and just like you it was reading 0. I think its because the pcm goes into a default setting

i solved the issue by using INPA by resetting the codes and adaptions, i was then able to read the 02 sensor V in INPA. The idle was still lumpy but it went away afterawhile. hope your situation is as easy to solve as it was for me. good luck.

Thanks for this.

The car isn't throwing any codes, and I've hit 'erase codes' on my OBD2 scanner.


Are you talking about using a desktop computer to reset the codes?

[gT-BMW]

Originally Posted by bmwe90320i-N46

Thanks for this.

The car isn't throwing any codes, and I've hit 'erase codes' on my OBD2 scanner.


Are you talking about using a desktop computer to reset the codes?

yes. I have a generic code scanner, it can read codes and give me live data but it wont reset the codes and adaptions unless it is a bmw specific code reader.

heres what INPA looks like

[bmwe90320i-N46]

Originally Posted by gT-BMW

yes. I have a generic code scanner, it can read codes and give me live data but it wont reset the codes and adaptions unless it is a bmw specific code reader.

heres what INPA looks like

Fantastic, thanks for that info. I reset the codes on my OBD scan tool, does INPA reset something different?

Could it be a reporting problem with my $100 scan OBD2 scan tool?


I've confirmed it's not a wiring/pin problem, the sensor is fine, and the pins are getting the same voltage on both downstream harness side connectors (tested with a multimeter). This means that the message is either not getting into the ECU, or isn't being reported back to me.

There is no engine light, but I'm still getting my hard start every SECOND time?
We put a new motor in it and ever since it's had this issue.


Any thoughts?


- Could this still be an INPA reset?
- Could it need a tune?

[SG1992]

I have the same issue
Had a coil pack failure, so replaced all 4 coils and spark plugs.
2 weeks later this issue came up.
Reading from OBD reader:
Bank 1 sensor 2 - no voltage. (Check engine light - PO430)
Bank 2 sensor 2 - works like normal

At the loom to o2 sensor connection :
Bank 1 sensor 2 : 12v for heating and .466v for signal
Bank 2 sensor 2 : same as above

I'll be checking my loom at the dme to see if there's anything going on there. Will advise if I find anything

[rick668876]

Did INPA reset fix this? I cleared all the adaptive on my e90 320i, loading MSV8.0 isn't a match for my N46, even though I still tried it, same result.
O2 B1S2 is reading 0.0 volts, but a multimeter test shows hearting and voltage is working with revs, power from car is .44 volts and running after heating voltage varies from above and below it directly taking readings from the O2 sensor plug whilst inline, also taking readings from inside the ECU box same result.
I also have the same problem with e87 120i so is this something that needs to reset software wise?
Anyone can help? please no assumptions just people with the same problem and how they fixed it much appreciated.

MAF voltage working 'and replaced ( also if the MAF is not 100% will this effect ECU from enabling the B1S2 O2? again will software reset do the trick?
if so how to rest it?

all o2 sensors replaced and working.
codes cleared ok but it will show up in IM check as O2 sensor fault.

Thank in advance.

[Turbomick]

Originally Posted by bmwe90320i-N46

Hi,

Very stuck here! I have a new catalytic converter and have 4 new oxygen sensors. No engine light now.

HOWEVER the car is starting rough and shuddering. When I connect my OBD2 Tool it's telling me that O2B1S2 (V) = 0.000 all the time, regardless of the car being on, off, accelerating, decelerating, driving or idle.

I have connected a multimeter across the two signal wires going into the ECM, and have used a test light to bridge the signal pins (not power pins) on the harness side connector. I would imagine this means the wiring in between the ECM and harness side connector is fine?
Have I got this right?


If not I assume there must be an internal problem in the ECU. Because I connected the multimeter to the signal wires near the ECU it gave a reading, meaning the ECU wires are connected inside.
For some reason the computer isn't reading the voltage?


Here's the weird bit:
Even when there isn't a sensor plugged into the other sensor 2, when the car is running it reads V = 0.440 always.


Is this a tuning problem?
Is this a wiring problem?
Is this an internal ECU problem?


Please help!

Hi.
Did you ever get to the bottom of this. This is exactly the stage I’m at my self.
Cheers Mick

[Bradco02]

Same issue here since got car bank 1 sensor 2 bank 2 sensor 2 also not showing voltage in OBD program

[BMW E87 120i]

I have the exactly the same problem here.
Is there any idea where this is coming from?
Anything that could work to fix this?

[BMW E87 120i]

I did the same thing as gT-BMW said.
First i installed inpa. For the N46 engine you have to select e85,e86 instead of e87. Because on the e87 you can’t select N46.

In inpa you can see the sensor is turned off.

i cleared the error. Next i cleared the adaptions.

After that the sensor was on again.

[alicine]

Hi guys i guess i have similar problem ,

I have BMW 116i (n45 e87)

i was having problem with acceleration on low speeds so i wanted to check with inpa the analog values .
When i read the values live, i realised O2 Sensor Add. Bank1 is stock something like -5.0v.

do you think is the same problem?

Here is a short video of values https://streamable.com/9v0nc5