Hello Everyone-
I encountered the dreaded Reduced Power nanny this weekend (while away from home on vacation, of course). It took me six hours to travel from NY to PA. Nothing better than crawling up the hills of I-88 & I-81 at 45 MPH!
I received the following Check Control messages when the issue occurred:
1. Engine Malfunction. Reduced Power.
2. Increased Emissions.
3. DSC fault
4. DBC fault
5. Start Assist fault
I assume the primary fault is the first one and the other four are resulting faults from the first. Anyway, the next day, all of the Check Control messages were gone and the car was running normally. No issues. I took the car to the stealership to have them check the codes and to look for any obvious issues. I was informed that everything looks OK mechanically and that they are recommending a SW update. If the SW update does not resolve the issue (the issue returns), they are recommending replacement of the DME.
The SW update sounds like they're guessing (as does the DME replacement), so I'm not ready to do either. It should be noted that I do
not have the most current SW release. Given the history on the M3 Throttle Valve Actuators, I requested the specific codes they found in the history file. Following are the codes identified:
1. CDBF - DME Throttle Actuator Bank 1
2. CD93 - DME BUS Off Throttle Valve
3. 5E19 - DSC Engine Management Interface
Great. In my non expert opinion, it would appear that I need to replace the TVA on Bank 1. Before I do that, I'd like to hear opinions based upon the above. The tech indicated that he did assess the TVA's and they were performing properly. However, the codes that are being thrown may indicate a problem. Also, I did not see the same list of Check Control messages from others with TVA issues. Thoughts? By the way, should I update the SW irrespective of the main issue?