My trans has been going into fail safe mode lately, also been throwing p0171 & p0174 obd codes. Last night, it seemed to go into fail safe & throw code p0174 (SES light) at the same time. I suspect MAF sensor. From what I've read on the web,the trans uses MAF for load info. This would seem to explain the p0171, p0174 running lean codes & trans fail safe mode.
Anyone else experienced this situation? Is the MAF a likely culprit? Would having a code read that displays bmw codes (peake research) be helpful in determining the cause.
the same thing has happened to my 540i and its terrible bitch were is the maf sensor loction and cost because iam thinking its a shift silinode or speed sensor in the trans high speed or low speed .email your reponse to bmw540i@q.com interested to find out what you did to remedy