SMG Fault 97 - Control Area Network
I've got a low mileage but city driven 2003 M3. It's not my daily driver very often but last two winters when I was traveling abroad I let a friend drive it in exchange for indoor heated storage. When I returned and drove the car, I noticed the SMG light and the Service Engine Soon lights were both on.
I brought her in to a respectable independent repair shop where the main BMW tech was a guy who had previously worked at the local BMW dealer. He said, firstly, the oil was slightly low and old. He also suggested it might not have been the right oil for the car. No idea how the latter happened.
The Service Engine Soon fault was a malfunctioning VANOS. Flushing the oil and replenishing with new and good oil cleared that fault and it hasn't re-appeared. Saved me a few grand that the pump itself seems fine.
Nagging issue is the SMG fault. They did the diagnostics and it returned fault SMG 97 which is related to the Control Area Network (CAN). The tech says he can clear the code and drive the car, but as soon as he applies the brake, the fault reappears. We've all driven the car and she doesn't appear to have any performance issues related to shifting. It's a mystery. The shop is frustrated, worked on the car for many hours (but only charged me for one, thankfully), and is ready to "give up". I've had a bad experience with the local dealer and, quite honestly, I'm at a loss as to other alternatives other than another shop.