[SnakeKouki]

Okay this is for a friend of mine with an IS300 using the NA 2JZ tranny. The car won't shift gears by itself. But if you put it in manual mode and shift with the buttons on the steering wheel it shifts fine. So basically in "D" it stays in 1st gear.

Does anyone have any ideas if it's a sensor or mechanical issue? Or what to try first? I know jack shit about automatics, and I'm just trying to get ideas to help him out.

A little back story, the car had an Aristo swap done to it. Used the tranny off the stock motor, but it was sent out to get built to hold some power. Upgraded valve body, torque converter and some billet parts and shit. Before the swap the car shifted in "D" fine.

 

[Alex L.]

Sensor/wiring problem. Start tracing wires and see if anything was left unplugged.

 

[SnakeKouki]

That's what I was thinking. Because if the car can shift manually why not by itself? Unless some sensor is bad or something. Another thing is the car was fitted with an AEM. This AEM I was told by my friend is a Honda AEM being piggy backed onto the stock ECU because it has something to do with the VVTI....The engine is not VVTI...Would the AEM or ECU have anything to do with the transmission not shifting right? Assuming all the sensors are fine and wiring is correct.

 

[Alex L.]

Never heard of that before. If that's the case, is he using the AEM or stock ECU to control the tranny?

 

[SnakeKouki]

I'm not sure. I'll ask him to find out from the place that is doing all the work on his car.