Intelligent Auto Transmission?
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From: Oxfordshire, UK
My Ride: Alpine White F11 520D SE 2013
Being a novice auto driver I noticed something that I thought was strange yesterday. Going down a reasonably steep hill I eased off the gas and the car?s speed increased to a point, due to gravity I?m assuming, but then sat at a steady 30mph. The revs were high but the transmission didn?t change up. Why is this? Does the car know it?s on an incline and not change up to prevent an increase in speed?
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From: Kuala Lumpur, Malaysia
My Ride: G30 530i M-sport
Model Year: 2018
What is your car type/spec? Could help with figuring this out.
I have the plain vanilla steptronic transmission, and have never noticed any engine braking of the sort that you described. I have achieved engine braking only by going into manual mode and manually selecting a gear that I want the car to hold. Indeed, this is exactly what the user manual intrsucts steptronic users to do when encountering steep gradients.
I have the plain vanilla steptronic transmission, and have never noticed any engine braking of the sort that you described. I have achieved engine braking only by going into manual mode and manually selecting a gear that I want the car to hold. Indeed, this is exactly what the user manual intrsucts steptronic users to do when encountering steep gradients.
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My Ride: G30 M550i
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Originally Posted by Cojones' post='484473' date='Oct 22 2007, 07:49 AM
Being a novice auto driver I noticed something that I thought was strange yesterday. Going down a reasonably steep hill I eased off the gas and the car?s speed increased to a point, due to gravity I?m assuming, but then sat at a steady 30mph. The revs were high but the transmission didn?t change up. Why is this? Does the car know it?s on an incline and not change up to prevent an increase in speed?
Yes, the car knows all!
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ah yes, that important bit of info...2004 530i plain old steptronic. Yes it was behaving like I imagined it would in Manual, I had to check I was in D a couple of times as it was (seemingly) strange behaviour.
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Okay, so if it's not hill descent control, then it's just the transmission being "smart" and using it's adaptive programs.
The following link will take you to a .pdf document that explains pretty much everything you want to know about the steptronic (pre-LCI):
http://forums.e60.net/index.php?auto......si&img=2002
Here's a small quote from the above document describing some of the things that were probably going on when you were going down the hill:
That ought to explain things a little better... 
The following link will take you to a .pdf document that explains pretty much everything you want to know about the steptronic (pre-LCI):
http://forums.e60.net/index.php?auto......si&img=2002
Here's a small quote from the above document describing some of the things that were probably going on when you were going down the hill:
Originally Posted by Steptronic .pdf from E60.net Technical Gallery
Driving downhill
If the EGS control unit detects downhill driving, it will automatically shift down a gear if the vehicle's speed picks
up. This enhances the engine's braking effect. A downshift is only effected if the engine speed is below the
maximum speed of the lower gear.
The EGS control unit detects downhill driving on the basis of signals from the throttle valve potentiometer (load),
wheel speed sensor (road speed) and brake light switch (brake activation).
Braking deceleration and automatic upshift
To decelerate the vehicle, the foot is taken off the gas and the brake depressed as necessary. The gearshift map
triggers an upshift when the throttle is closed. These gearshifts are not necessary in conjunction with brake
applications as they prevent the engine's braking effect from being exploited.
The intention to apply the brakes can often be anticipated from the accelerator pedal being rapidly released to the
zero position. If such an action is detected, the upshift is suppressed for as long as the accelerator pedal is in
the zero position and the vehicle is in overrun mode.
If the EGS control unit detects downhill driving, it will automatically shift down a gear if the vehicle's speed picks
up. This enhances the engine's braking effect. A downshift is only effected if the engine speed is below the
maximum speed of the lower gear.
The EGS control unit detects downhill driving on the basis of signals from the throttle valve potentiometer (load),
wheel speed sensor (road speed) and brake light switch (brake activation).
Braking deceleration and automatic upshift
To decelerate the vehicle, the foot is taken off the gas and the brake depressed as necessary. The gearshift map
triggers an upshift when the throttle is closed. These gearshifts are not necessary in conjunction with brake
applications as they prevent the engine's braking effect from being exploited.
The intention to apply the brakes can often be anticipated from the accelerator pedal being rapidly released to the
zero position. If such an action is detected, the upshift is suppressed for as long as the accelerator pedal is in
the zero position and the vehicle is in overrun mode.
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Joined: Mar 2007
Posts: 1,056
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From: Kuala Lumpur, Malaysia
My Ride: G30 530i M-sport
Model Year: 2018
You're a seemingly unquenchable source of information Rudy! Never knew there was such functionality on the "plain vanilla" Steptronic until now 
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From: Oxfordshire, UK
My Ride: Alpine White F11 520D SE 2013
Originally Posted by MacSid' post='484534' date='Oct 22 2007, 03:48 PM
You're a seemingly unquenchable source of information Rudy! Never knew there was such functionality on the "plain vanilla" Steptronic until now
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From: Oxfordshire, UK
My Ride: Alpine White F11 520D SE 2013
Originally Posted by Rudy' post='484526' date='Oct 22 2007, 03:13 PM
Okay, so if it's not hill descent control, then it's just the transmission being "smart" and using it's adaptive programs.
The following link will take you to a .pdf document that explains pretty much everything you want to know about the steptronic (pre-LCI):
http://forums.e60.net/index.php?auto......si&img=2002
Here's a small quote from the above document describing some of the things that were probably going on when you were going down the hill:
That ought to explain things a little better...
The following link will take you to a .pdf document that explains pretty much everything you want to know about the steptronic (pre-LCI):
http://forums.e60.net/index.php?auto......si&img=2002
Here's a small quote from the above document describing some of the things that were probably going on when you were going down the hill:
That ought to explain things a little better...
p.s. the link doesn't work for me, is there any other way i can get the doc?
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Joined: Mar 2004
Posts: 17,310
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From: Pittsburgh, PA USA
My Ride: G30 M550i
Model Year: 2018
Originally Posted by Cojones' post='484539' date='Oct 22 2007, 11:08 AM
p.s. the link doesn't work for me, is there any other way i can get the doc?
http://forums.e60.net/index.php?autocom=ga...si&img=2002
(There's currently a bug in the board software that screws up links to posts that have been edited...) :thumbsdown:
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