Quote:
Originally Posted by Qsilver7
The FTP drive cycle can be completed in approx 30 minutes of driving if there aren't any other underlying issues.
|
@Qsilver7, thanks for the clarification...that helps a lot. You're right, even I had driven over 3,000 miles since battery replacement, I don't think I had done the 5 minute idle in gear process by chance.
It seems like FTP can only be done reliably by a shop on a dyno? I don't live somewhere that allows me to perform the specified drive cycle in one swoop. A service consultant at a local BMW service center told me that it does not have to be done continuously nor in the specified order. I've been trying different variations with no success. This is my realistic version of the FTP drive cycle...
- Cold start for 2m10s (w/ headlights, A/C, rear defroster on)
- Drive on local streets (stop/go) for a few minutes to a street without stop signs/stop lights
- Drive ~22 mph for 3m15s
- Drive on local streets (stop/go) for a few minutes to a freeway onramp
- Drive ~55 mph for 15m
- Exit freeway and coast to stop (with brakes) and idle for 5m
There are some questions that came to mind while going through the drive cycles...
- For the specified idle and drive durations, how accurate do they need to be?
- Can I use cruise control to maintain speed?
- For the end of the 15m drive, when I coast to stop, can I apply the brakes?
- For the end of the 5m idle, should I shut off the engine or drive off?
- Is it possible that I have bad O2 sensors but not bad enough to trigger the check engine light?
- Could vacuum leak cause the O2 monitor to be not ready?
- Could a bad gas cap be a cause?
- For future battery replacement, is it possible to connect another battery in paralley to preserve computer memory to prevent this from happening again?