Pre-cat or post-cat?
Pending or current fault code?
What does its voltage look like at hot idle?

 

What I'm trying to look for is that when an o2 sensor fails.... does it throw an open circuit condition?


Pre cat.
Current code.
Voltage is 12v

This is a different m54b30 ms43 vehicle. You helped me with it. (I get more help here than on the e53 site)

Open control circuit or some bs ?

I've had those two errors for both pre sensors for 12 years

It's a known glitch that requires a reflash

There's an old post by jbeurotech about it

I printed it out ,I'll take a pic of it and upload tomm,I keep it in my glovebox

I just clear the light ,only time it's an issue is inspection time

For some reason getting the Evap ready on this car is a fkn pia

I have to do 3 drive cycles to the t

My mazda3 is ready in a 5 minute drive

Bmw

I did reflash dme to most current.

On this the pre cat bank 1 O2 wires were melted. I had to repair them. Bank 2 pre cat is good.

Also both post cat wires were melted under the car too. Fixed those, those are not throwing the open circuit.

 

Open control circuit or some bs ?

I've had those two errors for both pre sensors for 12 years

It's a known glitch that requires a reflash

There's an old post by jbeurotech about it

I printed it out ,I'll take a pic of it and upload tomm,I keep it in my glovebox

I just clear the light ,only time it's an issue is inspection time

For some reason getting the Evap ready on this car is a fkn pia

I have to do 3 drive cycles to the t

My mazda3 is ready in a 5 minute drive

Bmw

 

Lol can't believe I found it,do you have 2973 or 2974 ?

I get both

02 Sensor codes DO NOT REPLACE 02's

For everyone that gets a 02 fault and then replaces it think again about it. This is why I continuasly advacate diagnosisg parts not just using the codes heere is an example. We have had three cars this week that autozone diag bad 02 sensors and still have an issue. Hope this helps others that...

www.e46fanatics.com

 

Lol can't believe I found it,do you have 2973 or 2974 ?

I get both

02 Sensor codes DO NOT REPLACE 02's

For everyone that gets a 02 fault and then replaces it think again about it. This is why I continuasly advacate diagnosisg parts not just using the codes heere is an example. We have had three cars this week that autozone diag bad 02 sensors and still have an issue. Hope this helps others that...

www.e46fanatics.com

None of those that are in that thread. I'll pull it again in the morning.

 

I wonder what happ to jb

He is never here anymore and his sight is history

 

@wasp9166 my vert has the same bs evap crap. Drive cycle is ridiculous.

 

Part of the evap is the test pump cycle- it only triggers every other time.

And there are minimum drive time constraints, too. I finally found it in INPA
and now run it manually.

Frustratingly, finding a LEAK in that system is even harder.

Narrowband or wideband o2's?
I would be asking BMWscanner what it's seeing for o2 sensor input voltage,
and then cross check against INPA- the car doesn't check heater supply voltage,
for some odd reason, so it's probably grumpy about the signal it's getting back from the sensor.

t

 

What do you mean you run drive time constraints manually

 

I haven't found a setting to flip monitors on in INPA. That would be handy.....

@TobyB where is it at?

 

Wide band O2 sensors heating circuit should be less than 5 ohms. Having 12 V going to an open circuit heater is still a fault.

 

Bad sensor.

I tested it the ol fashioned way with a blow torch and multi meter.

No voltage generated while heating it up.

For those that don't know that trick......