[ABD]

I am driving an e92 335i. Recently I experienced some problems.

It started with my car resetting some of the settings on its own everfy now and then (date & time, fuel consumption reader km/L). Each time I reset the date/time and leave the car overnight, the data gets deleted the next morning shortly after I start the engine and I had to input the date and time all over again and again. There was also once where the fuel consumption reading mode was changed but that problem only occurred once and has since never reappeared. I had the car's battery checked at a respectable workshop thinking that it might be due to a battery drain issue but there was no issue with the battery, so now it is suspected that the problem might be an DME issue.

Whats worst, today I experienced gear changes. As I was driving in D mode, the car will at times switch from D to Manual on its own depending on which gear I was driving on while in D. Example, from D to M3 and back to D. It switches back to D after like 1 or 2 seconds.

Did anyone had a same problem before? My 335i has the N54 engine.

[Mr. 5]

If you have ever added a piggy back or if you have one now then check the connections going to the ECU. They may be loose.

[ABD]

I used to have the JB3 piggy but that was very long ago. I had my DME tuned directly and never had any issue for the last 12 months until a couple of days ago. Therefore loose connections should not be the issue.

[Mr. 5]

Originally Posted by ABD

I used to have the JB3 piggy but that was very long ago. I had my DME tuned directly and never had any issue for the last 12 months until a couple of days ago. Therefore loose connections should not be the issue.

You had your DME tuned by whom?

[ABD]

Its tuned by a local tuner in Singapore. My car generates 380bhp and 520Nm on the dyno.