Engine shutdown at 20mph - bad problem, or user error?
I was braking hard and spinning the wheel pretty quickly, so it is possible that I might have bumped the start/stop button with a stray finger. Will the car actually shut down immediately if you touch the start button while braking at 15-20mph?
This reminded me a bit to much of the end of the Fifth Gear test drive: http://www.youtube.com/watch?v=syoBXsYBFvs.
What do you think, car problem, or user error?
Thanks,
Paul

Which way did you turn? I could think of turning the steering wheel to the left and touching the gear lever, it would go to N at 20 mph, not to reverse! Then you would have had to touch the start button, less likely.
Did you press the brake pedal at full force? If brake boost disappears, you have to press a lot harder but it should still brake well (this isn't an SBC car).
Did you press the brake pedal at full force? If brake boost disappears, you have to press a lot harder but it should still brake well (this isn't an SBC car).
Talked to my service advisor, and, as expected, he was unhelpful. They'll run full diagnostics on it tomorrow, but this was just done less than 2 months ago and came up clean. Now I'm really worried that the car will do this to me again in a less opportune location and cause a major accident. Yuck.

With the explanation from pmrogers, it sounds like the brakes were not just operating without the booster, a man at better than average shape should not feel like the car had no brakes even after loss of brake boost.
Theoretically the ABS valves could stay at a position where they reduce brake power to avoid skid, but ABS brakes are so proven technology that this should not happen, at least not for all wheels at the same time.
A mystery to me at least, hopefully it gets resolved, or at least will not be seen again.
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Paul
wouldn't even know it had died until you hit the gas to go and looked at the dash to see it was lit up like a Christmas tree.
The difficult part was that my problem never through a fault so the dealer could not see what was going on. A few other guys had the same issue and what we ended up doing was changing the crank sensor which seemed to help. After changing it the car shut off one more time, changed it again and didn't happen again. I don't believe it happened to the new owner (another member here) either.
Like you, I just assumed I must have done s omething the first time. I had the car about a week and was on the Cross Bronx Exp. (bad place to stall
) in bumper to bumper (is there any other kind) traffic in 90 + degree weather. It was usually very hot when this happened. Anyway, after it died I figured I hit something or accidently hit a button. A few months later it did it again and I brought it in. They adjusted the idle speed. Several months later did it again. Brought it back in and spoke to the V.P. of the dealership. I've bought several cars from them and told her I was just glad it didin't happen with my wife driving or while the car was in motion. On the spot she said "I'll get you another car". edit: It looks like your car did completely shut off? If so, then it's a very similiar situation. The only time I experienced something where the car was moving was one day my salesguy let me take out an SL65 for a spin. coming up to an intersection and about to make a right hand turn, the car shut off. Not fun.
do a search on "stalling" in the E55 forum and you should find some info. there.

I do recall now that the S will definitely allow you to power down the engine while in D, at least when you are at a full stop. When I first got the car I had a bit of a problem with remembering to put it into park after pulling into a parking space. The car would let me stop the engine and then start drifting as soon as I took my foot off the brake.
Allowing you to stop the engine when the vehicle is halted is understandable, but I would sure hope that the the ignition button is disabled when in motion, or at least enforces a 1-second hold before responding. That said, I'll actually feel better about my car if I can reproduce the engine kill while in motion-- I'd rather face known bad engineering than an unknown problem.
Paul
Pressing Start/Stop button in Drive while moving
Pressing Start/Stop button in Reverse while moving
Pressing Start/Stop button in Drive while moving and braking
Pressing Start/Stop button in Reverse while moving and braking
All of the above had absolutely no effect. No lights, buzzers, warnings, etc.
Pressing Start/Stop button in Drive while stopped with foot on brake
Pressing Start/Stop button in Reverse while stopped with foot on brake
Pressing Start/Stop button in Neutral while stopped with foot on brake
These three things did NOT stop the engine, but DID cause the MFD to turn red and say "Gear Selector Lever in Park Position"
Pressing Start/Stop button in Park with or without foot on brake kills engine.
Pressing Start/Stop button in Drive while moving
Pressing Start/Stop button in Reverse while moving
Pressing Start/Stop button in Drive while moving and braking
Pressing Start/Stop button in Reverse while moving and braking
All of the above had absolutely no effect. No lights, buzzers, warnings, etc.
Pressing Start/Stop button in Drive while stopped with foot on brake
Pressing Start/Stop button in Reverse while stopped with foot on brake
Pressing Start/Stop button in Neutral while stopped with foot on brake
These three things did NOT stop the engine, but DID cause the MFD to turn red and say "Gear Selector Lever in Park Position"
Pressing Start/Stop button in Park with or without foot on brake kills engine.
I have experienced this, and it is also stated in the manual.
Apoligies to the original poster for straying off topic.
Last edited by cyclerider; Jul 20, 2007 at 09:48 AM.

Both are at the end driven by a computer, with electro hydraulic circuits.
Pressing Start/Stop button in Drive while moving
Pressing Start/Stop button in Reverse while moving
Pressing Start/Stop button in Drive while moving and braking
Pressing Start/Stop button in Reverse while moving and braking
All of the above had absolutely no effect. No lights, buzzers, warnings, etc.
Pressing Start/Stop button in Drive while stopped with foot on brake
Pressing Start/Stop button in Reverse while stopped with foot on brake
Pressing Start/Stop button in Neutral while stopped with foot on brake
These three things did NOT stop the engine, but DID cause the MFD to turn red and say "Gear Selector Lever in Park Position"
Pressing Start/Stop button in Park with or without foot on brake kills engine.
KEYLESS-GO*:
...
Keep in mind that turning off the engine using the KEYLESS-GO start/stop button alone will not automatically shift the transmission to park position P. Only when the driver’s door is opened, will the transmission automatically shift to park position P.
Even though this is possible, make it a practice to always shift into park position P before turning off the engine and removing the SmartKey from the starter switch, or when using KEYLESS-GO*, before turning off the engine with the start/stop button and opening the driver’s door.
SmartKey:
If you turn off the engine using the SmartKey and remove the SmartKey from the starter switch, the transmission will shift to park position P automatically. Keep in mind that turning off the engine with the SmartKey alone will not automatically shift the transmission to park position P. Only when the SmartKey is removed from the starter switch, will the transmission automatically shift to park position P.


