BMW F20 o2 sensor fuse location?

[azone11]

Hi,

My BMW just started to show yellow engine warning light. ODB fault code reading provided code P0414 which points to O2 sensor fault. I would like to check the fuse next but I have no idea what fuse is for this sensor. Can anybody advice with this matter?

[MarcoZandrini]

That code is for the secondary air pump and not an oxygen sensor. Basically it means “Secondary Air Injection System Switching Valve A Circuit Shorted.”

[azone11]

That code is for the secondary air pump and not an oxygen sensor. Basically it means “Secondary Air Injection System Switching Valve A Circuit Shorted.”

I'm sorry, I wrote a wrong code. The real code is P0141.

[MarcoZandrini]

Great question! BMW doesn’t seem to want to let owners have an detailed info about their car’s fuses. Typically, the fuses for the engine computer (5) and the oxygen sensor heater circuits are located under the hood. I bet your problem is a bad heater circuit for bank 1 sensor 2. This is the oxygen sensor that monitors the health of the catalytic converter for bank 1. I bet your car is a4 cylinder. So you have only bank 1. BMWs with 6 or more cylinders have 2 banks. Your culprit is likely the heater circuit in the post catalytic converter sensor.

[azone11]

It is 4 cyl engine. With this information I'm planning to change the sensor if it is not too hard to do it by myself. Haven't checked that yet.. I wonder, after sensor change, is the ODB code clearing enough for resetting the situation back to normal -> turning off the yellow engine light?

[MarcoZandrini]

Hard to say if the ses light will go out automatically. I changed the post-cat sensor on the wife’s Honda and the ses light went out by itself. Soak the oxygen sensor with a good penetrating oil before trying to remove it.

[azone11]

Surprisingly the ses light went off by itself today. I'm starting to wonder that could it have been a bad connection or such. Well, the issues does not seem so urgent anymore.