View Full Version : How to use a A/T ECU for manual transmission

06-29-2017, 07:39 AM
Hi there:
I am a new guy for here. I come from Taiwan,and I have a 98' celica gt swap 4th 3SGTE(from caldina gt-t st215w) and use stock M/T ECU for manual transmission by Engine modifier almost 3 year ago, and every thing is ok, no CEL no any trouble.

Then I got a mine's VX-ROM ECU but it is a A/T ECU,and I try to install it for manual transmission by myself, then the car can start up normally, run normally,but the max pressure could lock at 0.5 bar (this condition the ECU connect B-13(THO ATF oil temperature) open wire),then I jump the B-13 (THO ATF oil temperature) to B-22(THA intake air temperature), then the max pressure can increase to 0.6 bar,but also lock 0.6 bar...............

Could any bro teach me how to trick A/T ECU with manual transmission is best ,could I use THW(B-14 water temperature) jump wire to B-13 (THO ATF oil temperature) for trick......?

and NT+(A-16) NT-(A-15)[input shaft revolution sensor] 、NC+(A-14) NC-(A-26)[counter gear speed sensor] need to wire? Which pin can jump for ? or keep open is fine no effect for run?

Thank you very much for taking the time to read this post!

06-29-2017, 02:25 PM
When I did my Gen4 3sgte swap into my 89 GTS manual I used an automatic transmission ECU from the Caldina.

I had no problems boosting and was able to keep around 12-15lbs of boost (.8-1.1bar). Not sure if that helps at all though :-\

06-29-2017, 04:41 PM
When I did my Gen4 3sgte swap into my 89 GTS manual I used an automatic transmission ECU from the Caldina.

I had no problems boosting and was able to keep around 12-15lbs of boost (.8-1.1bar). Not sure if that helps at all though :-\
Could u teach me how to jump for the THO input ? or keep open wire? do u remain the function of TVSV unit to protect engine or not?
somebody tell me that can cancel the pipe between tvsv and actuator, and stuff actuator bypass side, then u can increase any pressure value what u want by pressure controller. I just know this way ,but I think if I never give some signal to THO, the ECU will set into protect mode to lock pressure value at .5bar as above description by my test result. If cancel tvsv then I can increase pressure by controller ,but I think that is also not good for engine.....

06-29-2017, 05:20 PM
You are going to need to use a resistor to trick the ecu into thinking the trans temp is warmed up. Would need to see the Temp / resistance graph for the temp sensor to tell you what resistor you need. It will be in the Engine service manual from Toyota.

06-30-2017, 09:22 PM
^ what he said. If you're going to disconnect the TVSV you need to add a boost controller, but I would only do that if the engine is otherwise happy. If the computer is pulling boost it's going to be changing a bunch of other parameters too.

07-01-2017, 02:28 AM
Do what ? Cancel tvsv and add a boost controller?

07-01-2017, 02:43 AM
I just jump THW to THO, but also same to lock at .5bar, maybe I really need to set variable resistance to THO and find out ohm to got similar voltage to feedback for ECU

07-03-2017, 02:10 PM
That would work.

07-03-2017, 04:46 PM
I add a variable resistance to THO and adjust similar voltage to feedback for ECU, the test result below
set 1.0v ==>boost pressure = 0.5 bar
0.92v==>boost pressure = 0.5 bar
2.7v==>boost pressure = 0.5 bar
2.01v==>boost pressure = 0.5 bar
but I feel if THO voltage at 2.01v and 2.7v, the accelerator response like more sensitive, feel easy to run than before(stock M/T ECU)

I think that TVSV is worked so limit the max boost pressure to protect engine or auto transmission cause I don't feedback(I don't know how to feedback) the NT+ NT- and NC+ NC- to ECU, so ECU can not get the transmission speed or shaft revolution signal.
Actually I have jump SPD(C-22) to NT+(A-16), and jump E1(B-17) to NT-(A-15),but I don't know is it effective to trick ECU,cause I study other technical book about other car of toyota (2008 sienna),the NT、NC waveform(sine wave) is different than SPD waveform(Square wave),and the frequency and amplitude also different..@@", so I really don't know how to trick..

07-05-2017, 10:39 AM
I know on the 2GR you dont need to trick anything. It will crank and run at full power while it thinks it is in park. I know some older toyotas you had to crank in Park and then put in Drive to get full power. You may not need the transmission speeds at all. AFAIK there is noone that has figured it out anyways.

07-05-2017, 04:30 PM
I thought Marc cracked the 2gr ECU? It eliminated the trans and emissions controls for those folks that are limited by their states....