Allison 1000
Allison 1000
I am interested in controlling an Allison 1000 with the MegaShift controller. I have done a little research into this transmission, and so far it seems that the current firmware might not support it. From what I have read so far, it looks like the newer Allison's have three solenoids to control line pressure, a main line pressure solenoid, an on coming shift pressure solenoid, and an off going shift pressure solenoid. They have 3 shift solenoids which seems pretty normal for a 5-8 speed auto, and finally a TCC solenoid. Thats a grand total of 7 solenoids on the '04 and newer Allison's. The '03 and older Allison's lack the main line pressure solenoid. '05 and earlier A1000's and 5 speeds, '06 and newer are 6 speeds. All versions have to be shifted sequentially. After looking breifly at the MegaShift application in TunerStudio, it doesn't appear that the Megashift is setup to control three line pressure solenoids. Can anyone confirm this, and if so is it something that could be easily added?
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Bernard Fife
- Posts: 1696
- Joined: Fri Apr 04, 2008 1:28 pm
Re: Allison 1000
383,
It depends on how the additional line pressure solenoids operate. Are they pulse-width-modulated? Do they run at a constant duty cycle when on? Or are they varied in response to some other parameter? If so, what is the logic used to control the solenoids (what gears, speeds, etc., and what PWM duty cycle under given conditions).
The GPIO board has 8 high current solenoid drivers (and 4 more low current drivers that could be connected to high current drivers), so that isn't a limiting factor. Sequential shift is already in the code, of course.
There is more on the info needed here: http://www.msgpio.com/manuals/mshift/newtrans.html
Lance.
It depends on how the additional line pressure solenoids operate. Are they pulse-width-modulated? Do they run at a constant duty cycle when on? Or are they varied in response to some other parameter? If so, what is the logic used to control the solenoids (what gears, speeds, etc., and what PWM duty cycle under given conditions).
The GPIO board has 8 high current solenoid drivers (and 4 more low current drivers that could be connected to high current drivers), so that isn't a limiting factor. Sequential shift is already in the code, of course.
There is more on the info needed here: http://www.msgpio.com/manuals/mshift/newtrans.html
Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
Re: Allison 1000
Lance
The three pressure solenoids are PWM at 1kHz. The TCC is PWM at 100Hz. The three shift solenoids are discrete on/off. I have yet to verify these myself. Most of the info I have found so far is from this site: http://www.4btswaps.com/forum/showthrea ... ide-thread They have done a very good job finding info about the Allison transmissions. From what I have seen so far, it looks like the on going/off going pressure solenoids could possibly be controlled together with the same output, and control the main line pressure solenoid seperately. My dad has an '08 Chevy truck with an A1000 trans in it, so I will try to borrow it sometime to verify its operation. I will try to get solenoid impedance, frequency, duty cycle, and see if I can figure out how the three pressure solenoids are operating.
The three pressure solenoids are PWM at 1kHz. The TCC is PWM at 100Hz. The three shift solenoids are discrete on/off. I have yet to verify these myself. Most of the info I have found so far is from this site: http://www.4btswaps.com/forum/showthrea ... ide-thread They have done a very good job finding info about the Allison transmissions. From what I have seen so far, it looks like the on going/off going pressure solenoids could possibly be controlled together with the same output, and control the main line pressure solenoid seperately. My dad has an '08 Chevy truck with an A1000 trans in it, so I will try to borrow it sometime to verify its operation. I will try to get solenoid impedance, frequency, duty cycle, and see if I can figure out how the three pressure solenoids are operating.