[svxistentialist]

Originally Posted by b3lha

Joe,

The JDM and Euro TCUs are probably the same hardware, but the software is different. Pin 4 signals the TCU to change shift maps. On a Euro TCU, you ground pin 4 to enable Economy mode. On a JDM car, you ground pin 4 to enable Power mode.

There are two ways you can make a power switch on a car with a Euro TCU:

1) Mess with the TPS signal as per the FAQ.
2) Swap in a JDM TCU and then remove the bulb from the Econ light on the dash. This will make your Econ switch into a Power switch. AFAICT the JDM TCU should work fine with the Euro transmission.

Phil.

Thanks Phil

As I have a JDM TCU sitting here, I might just do that to see if it works like you say.

Two questions occur; in the JDM car, we are accustomed to thinking the ECU has software that "restricts" the top speed to 180 kms/h. Would it be safe to presume the TCU, which handles the speed signal before the speedo, has no role in this? In other words, using a European ECU with a Japanese TCU should not impose the Japanese speed limit to the arrangement?

The other question is similar; the JDM ECU is tuned to use top grade petrol, while the Eu models are tuned to handle our rubbish. Would the JDM TCU be tuned in any way to suit the better grade petrol they enjoy? I presume not?

This is interesting all right. As I currently have the underdash area eviscerated to access the bloody TCU, I WILL stick in the Japanese one, just to see what lights up, what doesn't. What have I to lose except more skin off my knuckles?