R53 '04 S. About a month ago the Service Engine Soon light begins coming on every few ignition cycles. The only symptom
[SIZE=3][FONT=Calibri]Is a hunting idle sometimes, surging to up to 1800 rpm, then down to 1200, then staying at 800 or 1000 rpm.[/FONT][/SIZE]
[SIZE=3][FONT=Calibri]I pulled the code with the trip reset and got 672800. I couldn’t find that on any list. So, I stopped by Cincinnati Mini. For $130 they told me the code was “unexpected high idle”. Thanks for the great information. After another 2 hour inspection, they said it was getting “close to a low voltage condition”. And they would like to replace the battery for $325, test drive the vehicle, & see if that’s it or not. After that, maybe an alternator?[/FONT][/SIZE]
[SIZE=3][FONT=Calibri]I replaced the battery with a 7 year AC/Delco for $100, even though the battery seemed fine. It was holding 12.6 volts after sitting over the weekend and the at 14.2 volts while running. It’s been 3 weeks and the same code and problem now happens almost every ignition cycle. I was hoping to eventually set another code which was meaningful, but no such luck.[/FONT][/SIZE]
[FONT=Calibri][SIZE=3] [/SIZE][/FONT]
[SIZE=3][FONT=Calibri]Any other experiences with a Unexpected High Idle?[/FONT][/SIZE]

 

our engines are drive by wire (tiny motor opens and closes the butterfly plate in the intake) so to have a high or fluctuating idle my guess would be a leak somewhere or somehow. I'm not knowleged enough under the mini's hood to know if the plate can get stuck or flutter, but other things to check would be o2 sensors giving a false reading, etc. Usually those would throw a code though...