A650E auto trans solenoid reader

[dumbass]

ive been looking at how the 4 solenoids work on the a650e to get the 5 forward gears
it seems something basic could be made to control the solenoids to match
the gear lever position if the solenoids just come on and off

i need something to try it on so once i get the correct plug to suit the solenoid and inhibiotr and build the controller
and then ill go find a car to test it on

ill do more reading to see if working the solenoids with just an off or on will work

[amichie]

All four shift solenoids are just on/off. The other 3 are pwm. If you leave the other 3 disconnected the trans will still operate.

[dumbass]

would it operate ok enough to drive and not get the shits with it

ill have to print off pinout of the shifter plug if there is more wires than just the 4 shift solenoids

[amichie]

You would most likely get very harsh shifting, no lockup and with no throttle pressure control the trans would be running at max pressure all the time and most likely cook itself.

[dumbass]

ok
ive done heaps of basic controlelrs for a340 and havnt had issues with running
max line pressure
so hopefully the a650 is the same
i gues sill have to ring my transmission friend

thanks for your info

[jordan]

I'm no trans expert but I suspect not controlling the line pressure will increase losses in the transmission and may result in premature failure.

Let me know what your trans friend says I would like to know how accurately the line pressure needs to be controlled for efficient operation.

[dumbass]

well the a340s dont have any issues
just a slightly harsher change and i have not had anyone complain

not sure about the a650

[ElectronicMan]

Thanks Amichie for the info. it seems to be working on that A650E. Still testing and will keep you posted.

[amichie]

Update.

I have now got the A650E fitted into my MX83 and I am trying to run the transmission from my Arduino based controller. I have the 4 shift solenoids running from a 4 channel relay board and the three PWM solenoids running off a MOSFET board. I change the gears up and down with the cruise control stork.

At the moment I cant get it to go into second gear. It seems that it takes more than just selecting the shift solenoids to select second gear. You have to do some trickery with the PWM solenoids also. According to a toyota new car features article for the GS300 it says that the Lock up solenoid regulator is used like a accumulator to achieve the change into second gear.

I will keep trying and post up some pics etc when done.

[George]

At least it makes clear the origin of 'strange' behavior of old A650's : they would have significant lag when switchin 1-2 in slow traffic, and the lower the rpm, the harder it would shift. Maybe you should just increase line pressure by increasing duty cycle of its solenoid?

[ElectronicMan]

You gave us the answer in your signals. You first need to switch sol 3 on for one second then you play with the duty cycle of the lockup sol. Then you will get 2nd. The trick is to trend the Duty cycle according to load the get it to shift decent.

[amichie]

You gave us the answer in your signals. You first need to switch sol 3 on for one second then you play with the duty cycle of the lockup sol. Then you will get 2nd. The trick is to trend the Duty cycle according to load the get it to shift decent.

Hi Electronic Man

I tried something like that yesterday and I got a very firm shift out of first and into second. Not sure if I actually got second gear or just 1st gear with the torque converter locked up as it seemed like a very positive feel with no torque converter slip. I will try again today. I think I also have to reduce the line pressure to get the car to happily shift intp 2nd.

I wonder if I can just operate the O/D in first gear to get a simpler 2nd gear?? I might try and operate S4 in 1st gear and see what happens.

[amichie]

Just tried it out and operating s4 in first gear does nothing.

[ElectronicMan]

It is 2nd gear you feel. What sol 3 does is bleed off the pressure that goes to the lockup.Then the lockup will not engage. Then the feedback pressure controlling the lockup will activate the 2nd control sol. According to your signals you need to pulse the lockup the same time as you open sol3 for one second. the duty cycle will determine the engage pressure. then you need to increase the pressure afterward for a proper shift according to the load. It is n difficult one i know. If you send me an email address i will forward you some information on that part of the tranny.

[amichie]

Here is a pic of my Arduino based controller. You can see a board with 4 relays that are used to drive the shift solenoids
and a board with 4 MOSFETS that are used to drive the PWM solenoids.



You can see where I tapped in to the ECU to get power and sensor inputs like TPS etc.