openecu.org

Posted: **Fri Mar 03, 2006 7:02 am**

Not sure if this is the right forum (Couldn't really find one that fit). Just wondering if anyone knows how to change the ECU's initial IAM value? Thanks

Posted: **Fri Mar 03, 2006 8:32 am**

You need to find the adress of this parameter in your ROM and no way to go except dissassembling

Do you know the adress in RAM of IAM for your car ? If so, dissassemble your ROM with IDA and look for reference to this RAM adress, you should find quite fast the initial IAM parameter adress.

Posted: **Fri Mar 03, 2006 8:40 am**

Good point. I dunno why I didn't think of that, I'll give it a try. Thanks for the input!

Posted: **Fri Mar 03, 2006 10:12 am**

Jeramie wrote:Good point. I dunno why I didn't think of that, I'll give it a try. Thanks for the input!

Looks like the one for the A4SG900C is at 0x2A2AC... haven't tested it yet, though.

Posted: **Fri Mar 03, 2006 11:30 am**

Right

If we use 0x20124 as IAM adress in RAM while monitoring (as laready published by some US users), we can find some routines managing IAM in the AF421 code like this one:

Posted: **Fri Mar 03, 2006 11:37 am**

Wow you guys are quick.

To bad we don't have the same ecus

Hopefully I will get around to "trying" to take a look. IDApro is not exactly intuitive. :lol:

Posted: **Fri Mar 03, 2006 11:40 am**

Jeramie wrote:Wow you guys are quick.

To bad we don't have the same ecus

Hopefully I will get around to "trying" to take a look. IDApro is not exactly intuitive.

Jeramie --

What CalID are you running, and what's your IAM address?

I can pull it up in IDA and look for candidates for initial IAM.

Posted: **Fri Mar 03, 2006 11:53 am**

Kha0S wrote:
Jeramie wrote:Good point. I dunno why I didn't think of that, I'll give it a try. Thanks for the input!

Looks like the one for the A4SG900C is at 0x2A2AC... haven't tested it yet, though.

Are you planning on testing?

Posted: **Fri Mar 03, 2006 11:58 am**

Kha0S wrote:
Jeramie wrote:Wow you guys are quick.

To bad we don't have the same ecus

Hopefully I will get around to "trying" to take a look. IDApro is not exactly intuitive.

Jeramie --

What CalID are you running, and what's your IAM address?

I can pull it up in IDA and look for candidates for initial IAM.

AH792
A4TF500F

http://forums.openecu.org/viewtopic.php?t=94
Thats my image.

IAM 0x020120

Thanks, I eperciate it!

Posted: **Fri Mar 03, 2006 12:58 pm**

Looks like 0x2998D. Can't guarantee it, but try it out. Change it, flash, and pull IAM to see if it's changed.

Posted: **Fri Mar 03, 2006 1:04 pm**

Cool, I'll give it a try and see what happens. Thanks for your help.

Heads up I sent you a PM.

Posted: **Sat Mar 04, 2006 8:57 am**

I got a chance to edit the hex and flash the image and it work perfectly.

AH792
A4TF500F

Inital IAM Address = 0x2998D

openecu.org

Initial IAM Value

Initial IAM Value