Toyota A750f Transmission control
Toyota A750f Transmission control
Thanks
Paul
Re: Toyota A750f Transmission control
Newby question, If I have a pwm output set to 100%, is it the same a general ouput set to 'on'?
Paul
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Re: Toyota A750f Transmission control
This looks similar to the 4L60E and could probably be mostly accommodated with the current code, except for the 4-5th solenoid. You *might* be able to use the Lock-Up Feel Parameters (http://www.msgpio.com/manuals/mshift/4L60E_MT.html#ll) to control this solenoid with some small code changes (changing the conditions from being dependent on the TCC state and load to being dependent on the shift table and load).
You would also need changes to accommodate 5th gear in the shift table, etc.
Since a number of people seem to want to control 5 speed (and higher) transmissions, I will put this in the code (it won't be released for a little while, though - until we have more feedback on the current code - hopefully weeks rather than months).
In the meantime, you can study the A750f transmission docs, and let us know in detail how they line up with the MShift inputs and outputs:
http://www.msgpio.com/manuals/mshift/hardware.html
http://www.msgpio.com/manuals/mshift/4L60E_MT.html
http://www.msgpio.com/manuals/mshift/wiring.html
Lance.
Re: Toyota A750f Transmission control
Although, because the tcc is locked in 4th and 5th, it might also provide a little 'give' for the change into 5th.
Probably could get the same result unlocking the convertor on the gear change
Factory ECU monitors the input and output speed and determines how hard to pressurise the clutch and band circuits in 4th and 5th. I think if the controller was dedicated to the a750 it could be done as per factory, but not sure if it is necessary, it is still adjustable maually via pwm control. Once it is set correctly for proper shift it shouldnt need altering again.
Paul
Re: Toyota A750f Transmission control
it all lines up fine, except the 4,3,2,1 inputs to show when manual selector is each low gear, need to find 2 more inputs or I need to find another way of inputting 7 signals on one channel.
I will post up the shift tables, when I have converted them
Paul
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Re: Toyota A750f Transmission control
I can't read that table, it's a bit too small. However, I think you are saying that the shift lever position input requires 4 digital inputs. The 4L60E has 3 of these. The fourth we can either use an existing, but unused, input (most likely the 2/4WDinut, or possibly the the non-CAN MAP input, or the line pressure sensor input).
When I do the code mods (soon), I will put the 4/5th solenoid on the LUF output (i.e. PT3/Amp32 for the 4/5 solenoid and SPR2/PA0/VB2 for TCC) and the additional digital input on PE1/Amp5 (currently the 2/4WD input).
I suppose you could put in resistors and make the shit lever positon a variable voltage function read on a single ADC input like the Ford shifters, but with a lot of gears the differences between gears gets smaller and harder to read correctly under all conditions, so I wouldnt recommend this.
Lance.
Re: Toyota A750f Transmission control
As for the shifter inputs, I have P/N on one input, then R, then D. Need 4 more inputs, and only space for 2. So at this stage, in its current configuration, I can have the manual / auto and up down paddle shift OR the factory manual shifter inputs for low gear selection but not both.
I want the paddle switching feature, the reason I jumped on this controller, so I have to find a way of inputing the shifter selections.
I thought of analogue voltage inputs, but with 8 of them spread across 5 volts, not much separation. Perhaps I can use PN, R, and D as I have, then use an analogue input for 4321.
I will fix the table up, today
Paul
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Re: Toyota A750f Transmission control
You may not need 4 more inputs, it may be a pattern of inputs that defines the gears. With 3 inputs you can have up to 8 unique combinations (000, 001, 010, 011, 100, 101, 110, 111). This is what the 4L60E uses. 4 inputs gives up to 16 possible gear combinations.
It isn't immediately clear to me how your transmission shift lever inputs work, and I didn't find anything in a quick look through the PDF you posted (the outputs are shown, but I didn't see the inputs listed anywhere).
Lance.
Re: Toyota A750f Transmission control
Paul
PS I have added the table from last week as an Exel file
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Re: Toyota A750f Transmission control
It looks to me like there are 5 shifter position switches going to the ECM on pins 8, 11, 21, 19, and 10.
These appear to be laid out as follows:
pin 8 = Neutral
pin 11 = Reverse
pin 21 = Drive
pin 19 = 3rd
pin 10 = 2nd
(The stock shifter doesn't appear to have a 1st.)
How you read these depends on what you are going to do with the other electronics (engine, ABS,...). If you are going to do away with those, you could put voltage dividing resistors in the circuit and make the shift lever position voltage based (like the Ford shifters). You could even use a custom arrangement for this to get 1st - by modifying the stock shifter or using a ford shifter or something else.
If you want to piggy-back off the current config (and it's 12V pull-up), then 4 switches is enough. You would hook up pins 11, 21, 19, and 10 as the digital inputs. If these are all low, then you must be in P/N. If any one of them is pulled low, then that is the selected gear. If two or more are pulled low then there is an error in the shifter or the hardware.
Lance.