Cant Find Fuse P0050

[gregg3gs]

My car: 08 e70 4.8
My problem: P0050 - Oxygen Sensor B2 S1: Heating Circuit: Malfunction/Open Circuit

I understand that a fuse may be bad. I have spend an hr looking for the darn thing and cant find it.
How dumb of a manufacturer not to have labeled the fuses (my 1st and last BMW, sounds like)... but I digress.

Would someone please help me.
I need to locate the fuse and test it before I get a new o2 sensor.
I have looked under the glove box but all 30amp fuses appear to be ok.
I am looking my mind.

Beers to one who helps me. Thank You.



UPDATE: the write up is on 2nd page (sort of write up)

[Xtony]

There's another fuse box in the right rear panel of the truck. Tucked to the side of the fuse box is a guide to what each fuse covers.

[TerminatorX5]

is there an E-box in the engine bay? some fuses, relays could be there

[gregg3gs]

I have located two fuses, 40Amp, located under the cabin air filter.
Both are good.

As for other fuse panels... I have one in under glove box and one in the back passenger side next to tail light. I have no documents tucked in anywhere, my guess is previous owner has removed it.

Can someone scan their fuse layouts and email me or post on line.

I appreciate the help.


I will continue troubleshooting tomorrow.

[ard]

How did you diagnose the fuse bad? Did you measure the voltages at the connection to the O2 sensors and find no voltage?

This error is most common when an O2 is unplugged or a wire ripped.... on the E39 the fuse is under the ebox/air filter and is NOT well marked/documented.

Again, measure voltages at the O2 connection first, THEN look for fuses.

[Xtony]

I had codes 2C9C and 2C61 which were for Lambda probe heater front catalyst, control and Lambda probe front catalyst, electrical error. Ended up replacing the passenger side pre-cat sensor and all is well. I do a lot of DIY work and the pre-cat sensors on the V8 engine are a royal pain because of their location.

[gregg3gs]

Stopped by the dealer today and they said that I cant buy a replacement card with fuses listed on it.

If anyone has all fuse listing and layouts, please post them or email me the scans directly. My email -> [email protected]

[Xtony]

Just sent you pictures of the diagrams to your e-mail. If that doesn't work, send me a PM with your cell # and I'll send them to your phone. BTW, make sure you look closely for the card. It is neatly folded and tucked in the right side of the rear fusebox. It's really hard to find. All you see is a little tab sticking out.

[ard]

Originally Posted by ard

How did you diagnose the fuse bad? Did you measure the voltages at the connection to the O2 sensors and find no voltage?

This error is most common when an O2 is unplugged or a wire ripped.... on the E39 the fuse is under the ebox/air filter and is NOT well marked/documented.

Again, measure voltages at the O2 connection first, THEN look for fuses.

?

[gregg3gs]

UPDATE:

at the end of the day the problem was a bad O2 Sensor.

Wow, BMW could not make it any harder and more difficult to get to it and replace it.
Not only did I have to find a little boy to get to the O2 sensor, now I am gonna have to feed him Benihanas.

After driving over 500 miles this weekend all is well.