E4 Fuel trim bank 2, permissible range exceeded
 

After struggling a fixing a short (with much help from forum members) in one of my O2 sensors I now get the E4 Fuel Trim Bank 2 error message above. Using my basic scanner I see nothing out of order or non functioning with regard to the O2 system. Internet search is inconclusive as to what would throw this code. Would love some troubleshoot tips.


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You need to do an adaptation reset to determine if the problem is fixed or not.

You need a "second level" scanner to do this.

If you plan on DIYing a good scanner is a must have tool.
https://www.carsoft.com/bmw-sb/bmwpro20.html. https://www.foxwelldiag.com There are others, even the BMW diagnostic software but last I knew it required a Windows based laptop with old version of software. Many use a dedicated laptop as it takes a considerable amount of memory.

Thanks, my scanner allows for adaptation resets so I’ve done that. Will drive some tomorrow.

I replaced the MAF, repaired the DISA and replaced the Idle Control Valve as part of the stuff I did with the O2 short repair. Any chance either of those could have gone wrong or if caused a vacuum leak?


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Not that unusual a part is bad out of the box. If code comes up after a repair I check my work as the most likely cause of the problem. Have you cleared the code and see if it returns?

Yes, I cleared it, comes back 5 or so miles in. Seems like any vacuum leak or MAF trouble would throw banks one and two.

Haven’t drive after clearing adaptations this pm yet.


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What are the fuel trims and o2 sensors reading ? I think "Out of permissible range" is a lot, so I would be looking at the individual o2 sensor and wiring especially since you were working on them.

I Thought the same. Went back through the wiring I did and seems high and tight. Resistance and continuity all good. O2 data stream seems normal also, will post a picture later for my scanner.


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You know the OBDfusion app on an iphone or android phone along with an OBD2 wifi reader Is really a fantastic tool for measuring fuel trims and diagnosing fuel trim related problems.

I have four BMW's with the M54 engine and I have used it several times.

The folks on E46fanatics are all over this tool. There is a whole write-up on how to set it up, capture logs and how to read the output...

https://www.e46fanatics.com/threads/...-jfoj.1097893/

Here are some pics from my scanner

https://uploads.tapatalk-cdn.com/202...0b215fa026.jpg
https://uploads.tapatalk-cdn.com/202...0e2965e6bb.jpg
https://uploads.tapatalk-cdn.com/202...b0f2388f2a.jpg


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