As the title states, I was just wondering if it was possible, to swap out the TH ecu for a TJ one.

Other than the fact (from what I've been told/gather) the TH is not flashable, whereas the TJ is, are there any other real gains to be had from changing to TJ ecu (if possible)?. I'm looking to get a tune soon and apparently the TH's ecu couldn't be tuned.

No real issues you just need to remove the immobiliser with ecuflash or get mitsu to recode the car

Tj ecu will allow you to use tiptronic on the 4 speed auto.

No real issues you just need to remove the immobiliser with ecuflash or get mitsu to recode the car

Awesome, is it a big difference between a normal ecu and a vrx ecu?



Tj ecu will allow you to use tiptronic on the 4 speed auto.

Haha, that's pretty cool..but I have a 5spd manual lol

Awesome, is it a big difference between a normal ecu and a vrx ecu?




Haha, that's pretty cool..but I have a 5spd manual lol

All tj ecus should work and should be the same in your case for manual?

As the title states, I was just wondering if it was possible, to swap out the TH ecu for a TJ one.

Yes. As someone else noted, the immobiliser has to be disabled. If you weren't already aware, the manual and automatic ECUs are different and you would need to find one of the right type. TL/TW ECUs are not recommended.


Other than the fact (from what I've been told/gather) the TH is not flashable, whereas the TJ is, are there any other real gains to be had from changing to TJ ecu (if possible)?. I'm looking to get a tune soon and apparently the TH's ecu couldn't be tuned.

TH ECUs are definitely reflashable with the right setup, however at the moment they aren't as well supported as the TJ onwards ECUs due to lack of published map definitions.

All tj ecus should work and should be the same in your case for manual?
Manual and auto 3rd gen v6 ECUs are different: different connectors, and different internal hardware.

Yes. As someone else noted, the immobiliser has to be disabled. If you weren't already aware, the manual and automatic ECUs are different and you would need to find one of the right type. TL/TW ECUs are not recommended.



TH ECUs are definitely reflashable with the right setup, however at the moment they aren't as well supported as the TJ onwards ECUs due to lack of published map definitions.

Yeah I did know that. So does that mean I can't have my immobliser at all? Or it wont recognise the new ECU?

Yeah I did know that. So does that mean I can't have my immobliser at all? Or it wont recognise the new ECU?
The two main parts to the immobiliser function are in the BEM and in the ECU. The ECU part expects to recognise the BEM part; when it can't, it shuts down the engine and won't support a restart attempt until the ignition switch is set to OFF.

There appears to be a difference between the way the ECU part of the immobiliser function works between the two series; the obvious things (like copying the immobiliser code from a TH ECU to a TJ ECU) have been tried without success. Without knowing how to make the later ECU code respond in a way that recognises the code stored in the BEM (which is unchangeable once set), successfully using a later ECU requires the ECU's part of the immobiliser function be disabled so that the engine can be run. The BEM part of the immobiliser function is unchanged, and restoring the original ECU would see the immobiliser function work normally.

The two main parts to the immobiliser function are in the BEM and in the ECU. The ECU part expects to recognise the BEM part; when it can't, it shuts down the engine and won't support a restart attempt until the ignition switch is set to OFF.

There appears to be a difference between the way the ECU part of the immobiliser function works between the two series; the obvious things (like copying the immobiliser code from a TH ECU to a TJ ECU) have been tried without success. Without knowing how to make the later ECU code respond in a way that recognises the code stored in the BEM (which is unchangeable once set), successfully using a later ECU requires the ECU's part of the immobiliser function be disabled so that the engine can be run. The BEM part of the immobiliser function is unchanged, and restoring the original ECU would see the immobiliser function work normally.


Hmm, that seems fair enough. Is it possible to maintain the immoboliser through a third party system? Or is it the same thing?

The two main parts to the immobiliser function are in the BEM and in the ECU. The ECU part expects to recognise the BEM part; when it can't, it shuts down the engine and won't support a restart attempt until the ignition switch is set to OFF.

There appears to be a difference between the way the ECU part of the immobiliser function works between the two series; the obvious things (like copying the immobiliser code from a TH ECU to a TJ ECU) have been tried without success. Without knowing how to make the later ECU code respond in a way that recognises the code stored in the BEM (which is unchangeable once set), successfully using a later ECU requires the ECU's part of the immobiliser function be disabled so that the engine can be run. The BEM part of the immobiliser function is unchanged, and restoring the original ECU would see the immobiliser function work normally.

Hmm, that seems fair enough. Is it possible to maintain the immoboliser through a third party system, or is it the same deal?