IS300 MAuto Mod - Ultimate manual swap wiring - NO CEL - INSTANT POWER - NO PARTS NEEDED - AUTO ECU!

21546 Views 46 Replies 16 Participants Last post by jesve, 7 d ago

marko.dodo

Discussion Starter · Jun 8, 2020 (Edited)

Hello!
I'm new to this forum and I figured out how to wire the stock auto ecu without ANY error codes AND with smooth power delivery!
I want to share this easy and free mod with you guys since manual ECUs are getting more rare and expensive and are only available on the US market.

The first thing you need to do is to wire up the park/neutral position switch and AT indicator switch connector correctly.
It was plugged into the AT and looks like this:

(picture from Curran)

Connecting the two black wires together allows your engine to start.

Connecting the two red (red/black and red/blue) wires to your reverse light switch lets your reverse lights light up when put in reverse.

This is the way people did it until now. the problem is, the ECU thinks the AT is in no gear while driving, it only knows when you are going in reverse.
This is also the reason for the bad throttle response and no smooth power delivery.

Connect the yellow/green wire to the red/blue wire to tell the ECU that the AT is in 2nd gear.

We have a few problems now:
As soon as you put your car in reverse, you will get an error code because the ecu thinks it is in reverse AND 2nd.
This is solved by simply cutting the red/black wire (connector D, pin 5) on the ecu connector.

Now the ECU will never know when you put your car in reverse. fooled.

Next thing you want to do is, to put the car in 1st/L since this is the only gear the ECU doesnt try to shift. This is done by connecting the two wires on one of the connector in the drivers compartment where your AT shift lever was.
Connect the Yellow/Green wire to the Green/Yellow wire.

When you are already here, you can also activate the ECT/PWR mode. I dont know if this does something, but it cant be bad.
Connect brown and blue/white:

now your cluster should show L and ECT:

Now you will have two error codes left, AT input RPM and output RPM. This is where it gets tricky, but my genius found the solution:
Connect the two Sensor+ wires from the rpm sensors to the CAM sensor! Because its a VR-type sensor, we can share the signal.
So go back to the ECU and connect O/D Clutch Speed Sensor (D, 21, red) and vehicle speed sensor (D, 23, blue/yellow) to the CAM sensor input (E, 29, green).

FOOLED!

You are done! assuming you already dealt with the transmission solenoids and temperature sensor.
the easyest way is to open the AT and unscrew the solenoids and the temperature sensor. now you can pull the whole harness out of the AT and plug it into the car.
put it in a bag or something and strap it to the car. Dont forget that all the solenoids with only one wire need to be grounded! screw them together in pairs and connect them with ring cable lugs to the car. i used the brake line bracket near the tranmission.

If you want a more elegant way or you still need the AT, you also can solder some resistors in place of the solenoids. Note that the 10 Ohm resistors have to be at least 20Watts or they will burn. This is the connector from the CAR, looking onto it as you were the other one wanting to plug into it

here a diagram for better understanding, or if you want to go from the ECU directly. watch out, the resistors DO get hot! they will melt any plastic they are attached to!

The only thing missing now, is working cruise control. I already figured out a way to do it, but it would cost arount 100$ to do it.

I hope i could help many guys with my solution and save tons of caashh!

))

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