993 Tiptronic question
05-15-2012, 03:35 AM
#2
Rennlist Member
I haven't owned a tip 993 in years.
But I do remember something like that. I believe it starts in 2nd from park and stop. But if you put it in reverse just prior to drive, it will start in 1st. Some sort of weird Porsche thing.
But I do remember something like that. I believe it starts in 2nd from park and stop. But if you put it in reverse just prior to drive, it will start in 1st. Some sort of weird Porsche thing.
05-15-2012, 02:57 PM
#5
Rennlist Member
Here's a quote from a post I made a few years ago.
The tip system is complex. It takes seven pages in the Factory Repair Manual to describe the operation. In the automatic program the electronic transmission control system selects among 5 different shift point maps from SC1 for "comfortable" driving to SC5 for "very sporting" driving. The inputs are shift selector, throttle position, rpm, speed, lateral acceleration, and longitudinal acceleration.
Here's some stuff plagiarized from the manual.
To go straight to SC5 the "accelerator is depressed suddenly and abruptly".
"When the accelerator is released rapidly ahead of curves (throttle control speed), the control unit detects this driving situation and prevents shifting."
"The transverse acceleration sensor sends a signal to the control unit as soon as vehicle exceeds the transverse acceleration thresholds at which no shifts should be made. The engaged gear then remains selected regardless of any accelerator movement."
The “kickdown latching” allows the max rpm shiftpoints to be used at less than full throttle. “The function is started when the kickdown switch is actuated and the accelerator is released rapidly.” “The kickdown shift speeds remain active until the accelerator is released to 50% of the full-throttle position.”
If you want to start out in first gear instead of second the throttle angle must be >35% in the “D” position or the shift selector must be in “3”, “2”, or “1”.
And on and on with “adaptive pressure control, “uphill and downhill detection”, “warm-up map”, “transmission protection at high ATF temperatures” …
Here's some stuff plagiarized from the manual.
To go straight to SC5 the "accelerator is depressed suddenly and abruptly".
"When the accelerator is released rapidly ahead of curves (throttle control speed), the control unit detects this driving situation and prevents shifting."
"The transverse acceleration sensor sends a signal to the control unit as soon as vehicle exceeds the transverse acceleration thresholds at which no shifts should be made. The engaged gear then remains selected regardless of any accelerator movement."
The “kickdown latching” allows the max rpm shiftpoints to be used at less than full throttle. “The function is started when the kickdown switch is actuated and the accelerator is released rapidly.” “The kickdown shift speeds remain active until the accelerator is released to 50% of the full-throttle position.”
If you want to start out in first gear instead of second the throttle angle must be >35% in the “D” position or the shift selector must be in “3”, “2”, or “1”.
And on and on with “adaptive pressure control, “uphill and downhill detection”, “warm-up map”, “transmission protection at high ATF temperatures” …
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05-16-2012, 04:38 AM
#9
Racer
Join Date: Nov 2005
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Peter
D by default starts off in 2nd gear and when you stop it returns to 2nd gear. That is normal. As others have said, in full auto mode, if u want to the system to engage first gear, you need to select 3 or lower gear.
anyway, most of us use the manual mode even on daily drives as the kick down is quite slow.
D by default starts off in 2nd gear and when you stop it returns to 2nd gear. That is normal. As others have said, in full auto mode, if u want to the system to engage first gear, you need to select 3 or lower gear.
anyway, most of us use the manual mode even on daily drives as the kick down is quite slow.
05-16-2012, 07:31 AM
#11
Racer
I read here somewhere that there is a way to teach the tip tranny to select 1st when you come to a stop, it involved someting like shifting back to 1st in manual mode as your speed came to 10mph or lower and doing this a number of times. I tried it several times but could never get it to learn.
Bad Porschey, No treat for you...
I have noticed that it sometimes selected 1st from first take off in winter but only a handful of times in all the time I have had it, and never once it has warmed up a little.
Bad Porschey, No treat for you...
I have noticed that it sometimes selected 1st from first take off in winter but only a handful of times in all the time I have had it, and never once it has warmed up a little.
05-16-2012, 05:30 PM
#12
Rennlist Member
If you want to start out in first gear instead of second the throttle angle must be >35% in the “D” position or the shift selector must be in “3”, “2”, or “1”.
I read here somewhere that there is a way to teach the tip tranny to select 1st when you come to a stop, it involved someting like shifting back to 1st in manual mode as your speed came to 10mph or lower and doing this a number of times. I tried it several times but could never get it to learn.
Bad Porschey, No treat for you...
I have noticed that it sometimes selected 1st from first take off in winter but only a handful of times in all the time I have had it, and never once it has warmed up a little.
Bad Porschey, No treat for you...
I have noticed that it sometimes selected 1st from first take off in winter but only a handful of times in all the time I have had it, and never once it has warmed up a little.
I'll have to look it up again (in the factory repair manual) but I believe 'moving off in second gear' is enabled after 'warm-up'.
